Bioenergetics

@inproceedings{lotka1922contribution11,
    author = "Lotka, A. J",
    title = "Contribution to the energetics of evolution",
    year = "1922",
    booktitle = "Proceedings of the National Academy of Sciences, v. 8, p. 147-155",
    note = "talkorigins\_source = {true}; raw\_reference = {Lotka, A. J., 1922, Contribution to the energetics of evolution: Proceedings of the National Academy of Sciences, v. 8, p. 147-155.}"
}

@misc{brody1945bioenergetics6,
    author = "Brody, S",
    title = "Bioenergetics and Growth",
    year = "1945",
    howpublished = "New York, Van Nostrand Reinhold, 1023 p",
    note = "talkorigins\_source = {true}; raw\_reference = {Brody, S., 1945, Bioenergetics and Growth: New York, Van Nostrand Reinhold, 1023 p.}"
}

@misc{odum1955times12,
    author = "Odum, H. T. and Pinkerton, R. C",
    title = "Time's speed regulator",
    year = "1955",
    howpublished = "the optimum efficiency for maximum power output in physical and biological systems: American Scientist, v. 43, no. 2, p. 331-343",
    note = "talkorigins\_source = {true}; raw\_reference = {Odum, H. T., and Pinkerton, R. C., 1955, Time's speed regulator: the optimum efficiency for maximum power output in physical and biological systems: American Scientist, v. 43, no. 2, p. 331-343.}"
}

@article{swanson1957bioenergetics,
    author = "Swanson, C. P. and Szent-Gyorgyi, Albert",
    title = "Bioenergetics",
    year = "1957",
    journal = "AIBS Bulletin",
    url = "https://doi.org/10.2307/1292470",
    doi = "10.2307/1292470",
    number = "5",
    pages = "52",
    volume = "7"
}

@article{mo1959bioenergetics,
    author = "M O, \\&NA;",
    title = "Bioenergetics",
    year = "1959",
    journal = "The American Journal of the Medical Sciences",
    url = "https://doi.org/10.1097/00000441-195903000-00037",
    doi = "10.1097/00000441-195903000-00037",
    pages = "411",
    volume = "237"
}

@misc{broda1975the5,
    author = "Broda, E",
    title = "The Evolution of the Bioenergetic Processes",
    year = "1975",
    howpublished = "Oxford, Pergamon",
    note = "talkorigins\_source = {true}; raw\_reference = {Broda, E., 1975, The Evolution of the Bioenergetic Processes: Oxford, Pergamon.}"
}

A study of the evolution of bioenergetics, this book examines total starvation and the physical aspects of metabolism, as well as the metabolism of the starving animal. It discusses food as fuel and looks at food and population.

@book{openalexw1562852527,
    author = "Kleiber, Max",
    title = "The Fire of Life: An Introduction to Animal Energetics",
    year = "1975",
    abstract = "A study of the evolution of bioenergetics, this book examines total starvation and the physical aspects of metabolism, as well as the metabolism of the starving animal. It discusses food as fuel and looks at food and population.",
    openalex = "W1562852527"
}

@article{alexander1977fast2,
    author = "Alexander, R. M",
    title = "Fast locomotion of some African ungulates",
    year = "1977",
    journal = "Journal of Zoology, v. 183, p. 291-300",
    note = "talkorigins\_source = {true}; raw\_reference = {Alexander, R. M., 1977, Fast locomotion of some African ungulates: Journal of Zoology, v. 183, p. 291-300.}"
}

@article{green1977bioenergetics,
    author = "Green, D. E.",
    title = "Bioenergetics The Evolution of Bioenergetic Processes E. Broda",
    year = "1977",
    journal = "BioScience",
    url = "https://doi.org/10.2307/1297685",
    doi = "10.2307/1297685",
    number = "11",
    openalex = "W2323959819",
    pages = "751-751",
    volume = "27"
}

@article{na1977bioenergetics,
    author = "\\&NA;",
    title = "Bioenergetics",
    year = "1977",
    journal = "Journal of Clinical Engineering",
    url = "https://doi.org/10.1097/00004669-197707000-00024",
    doi = "10.1097/00004669-197707000-00024",
    number = "3",
    pages = "279",
    volume = "2"
}

@misc{fedak1979reappraisal9,
    author = "Fedak, M. A. and Seeherman, H. J",
    title = "Reappraisal of energetics of locomotion shows identical cost in bipeds and quadrupeds including ostrich and horse",
    year = "1979",
    howpublished = "Nature, v. 282, p. 713-716",
    note = "talkorigins\_source = {true}; raw\_reference = {Fedak, M. A., and Seeherman, H. J., 1979, Reappraisal of energetics of locomotion shows identical cost in bipeds and quadrupeds including ostrich and horse: Nature, v. 282, p. 713-716.}"
}

@book{gessamen1979methods10,
    author = "Gessamen, J. A",
    title = "Methods of Estimating the Energy Cost of Free Existance, in Gessamen, J. A., ed., Ecological Economics of Homeotherms",
    year = "1979",
    publisher = "Logan, Utah, Utah State University Press, p. 3-31",
    note = "talkorigins\_source = {true}; raw\_reference = {Gessamen, J. A., 1979, Methods of Estimating the Energy Cost of Free Existance, in Gessamen, J. A., ed., Ecological Economics of Homeotherms: Logan, Utah, Utah State University Press, p. 3-31.}"
}

@incollection{bakker1980dinosaur3,
    author = "Bakker, R. T",
    editor = "Thomas, D. K. and Olson, E. C.",
    title = "Dinosaur heresy-dinosaur renaissance: Why we need endothermic archosaurs for a comprehensive theory of bioenergetic evolution",
    year = "1980",
    booktitle = "A Cold Look at the Warm Blooded Dinosaurs",
    publisher = "Washington, D.C., American Association for the Advancement of Science, p. 351-462",
    note = "talkorigins\_source = {true}; raw\_reference = {Bakker, R. T., 1980, Dinosaur heresy-dinosaur renaissance: Why we need endothermic archosaurs for a comprehensive theory of bioenergetic evolution, in Thomas, D. K., and Olson, E. C., eds., A Cold Look at the Warm Blooded Dinosaurs: Washington, D.C., American Association for the Advancement of Science, p. 351-462.}"
}

@misc{caple1983the7,
    author = "Caple, G. R. and Balda, R. P. and Willis, W. R",
    title = "The physics of leaping animals and the evolution of preflight",
    year = "1983",
    howpublished = "American Naturalist, v. 121, p. 455-476",
    note = "talkorigins\_source = {true}; raw\_reference = {Caple, G. R., Balda, R. P., and Willis, W. R., 1983, The physics of leaping animals and the evolution of preflight: American Naturalist, v. 121, p. 455-476.}"
}

@incollection{adams1987the1,
    author = "Adams, D",
    editor = "ch. 1-6 of Currie, P. J. and Koster, E.",
    title = "The bigger they are, the harder they fall: Implications of ischial curvature in ceratopsian dinosaurs",
    year = "1987",
    booktitle = "Fourth Symposium on Mesozoic Terrestrial Ecosystems",
    publisher = "Drumheller, Canada, Tyrrell Museum",
    note = "talkorigins\_source = {true}; raw\_reference = {Adams, D., 1987, The bigger they are, the harder they fall: Implications of ischial curvature in ceratopsian dinosaurs, in ch. 1-6 of Currie, P. J., and Koster, E., eds., Fourth Symposium on Mesozoic Terrestrial Ecosystems: Drumheller, Canada, Tyrrell Museum.}"
}

@misc{bakker1987the4,
    author = "Bakker, R. T",
    title = "The return of the Dancing Dinosaurs, in Czerkas, S. J., and Olson, E. C., eds., Dinosaurs Past and Present, 1",
    year = "1987",
    howpublished = "Los Angeles, Natural History Museum of Los Angeles County, p. 38-69",
    note = "talkorigins\_source = {true}; raw\_reference = {Bakker, R. T., 1987, The return of the Dancing Dinosaurs, in Czerkas, S. J., and Olson, E. C., eds., Dinosaurs Past and Present, 1: Los Angeles, Natural History Museum of Los Angeles County, p. 38-69.}"
}

@misc{carrier1987the8,
    author = "Carrier, D. R",
    title = "The evolution of locomotion stamina in tetrapods",
    year = "1987",
    howpublished = "Circumventing a mechanical constraint: Paleobiology, v. 13, p. 326-341",
    note = "talkorigins\_source = {true}; raw\_reference = {Carrier, D. R., 1987, The evolution of locomotion stamina in tetrapods: Circumventing a mechanical constraint: Paleobiology, v. 13, p. 326-341.}"
}

Arthropods possess spectacular diversity in locomotor design. Yet it is not clear what unique constraints, if any, variation in design imposes on mechanics, metabolic energy cost or endurance during terrestrial locomotion. In the present study metabolic energy cost and endurance on a treadmill are measured for an arthropod, the eight-legged sideways travelling ghost crab, Ocypode quadrata (Fabricius). In a second paper the mechanics of locomotion are determined during walking and running over a force plate. Severe limitations in O2 uptake during exercise are not inherent in the design of a crab’s O2 transport system, which consists of gills and an open circulatory system. The ghost crab’s capacity to elevate oxygen consumption rapidly is correlated with a lesser dependence on anaerobic sources than observed in other crab species. Accelerated glycolysis contributed at the onset of submaximal exercise, before O2 uptake adjustments were completed, but played only a minor role during steady-state exercise. O. quadrata elevated 6·4-to 8-fold above resting rates. The ghost crab’s maximal oxygen consumption was not different from that of an ectothermic vertebrate of the same body mass and temperature, such as a lizard, that uses lungs and a closed circulatory system. The minimum metabolic energy necessary to move 1 g of crab 1 km (Cmin) decreased as a function of body mass and age. Cmin was comparable to that predicted for vertebrates of a similar body mass and, therefore, appears to be relatively independent of locomotor design. This is consistent with the hypothesis that a similarity in the energetic properties of muscle and elastic structures may result in similar metabolic costs of locomotion. Endurance capacity did not increase with body mass, as predicted from interspecific comparisons of mammals and lizards. Instead, endurance capacity correlated with the speed at which oxygen consumption was maximal. Mean endurance capacity for ghost crabs was similar to that found for lizards, but was far less than the values predicted for mammals. Ghost crabs could only sustain a slow walk. Running at speeds 20 times faster is possible for short periods, but not without the aid of anaerobic metabolism.

@article{full1987locomotion,
    author = "Full, Robert J.",
    title = "Locomotion Energetics of the Ghost Crab: I. Metabolic Cost and Endurance",
    year = "1987",
    journal = "Journal of Experimental Biology",
    abstract = "Arthropods possess spectacular diversity in locomotor design. Yet it is not clear what unique constraints, if any, variation in design imposes on mechanics, metabolic energy cost or endurance during terrestrial locomotion. In the present study metabolic energy cost and endurance on a treadmill are measured for an arthropod, the eight-legged sideways travelling ghost crab, Ocypode quadrata (Fabricius). In a second paper the mechanics of locomotion are determined during walking and running over a force plate. Severe limitations in O2 uptake during exercise are not inherent in the design of a crab’s O2 transport system, which consists of gills and an open circulatory system. The ghost crab’s capacity to elevate oxygen consumption rapidly is correlated with a lesser dependence on anaerobic sources than observed in other crab species. Accelerated glycolysis contributed at the onset of submaximal exercise, before O2 uptake adjustments were completed, but played only a minor role during steady-state exercise. O. quadrata elevated 6·4-to 8-fold above resting rates. The ghost crab’s maximal oxygen consumption was not different from that of an ectothermic vertebrate of the same body mass and temperature, such as a lizard, that uses lungs and a closed circulatory system. The minimum metabolic energy necessary to move 1 g of crab 1 km (Cmin) decreased as a function of body mass and age. Cmin was comparable to that predicted for vertebrates of a similar body mass and, therefore, appears to be relatively independent of locomotor design. This is consistent with the hypothesis that a similarity in the energetic properties of muscle and elastic structures may result in similar metabolic costs of locomotion. Endurance capacity did not increase with body mass, as predicted from interspecific comparisons of mammals and lizards. Instead, endurance capacity correlated with the speed at which oxygen consumption was maximal. Mean endurance capacity for ghost crabs was similar to that found for lizards, but was far less than the values predicted for mammals. Ghost crabs could only sustain a slow walk. Running at speeds 20 times faster is possible for short periods, but not without the aid of anaerobic metabolism.",
    url = "https://doi.org/10.1242/jeb.130.1.137",
    doi = "10.1242/jeb.130.1.137",
    number = "1",
    openalex = "W2293796457",
    pages = "137-153",
    volume = "130",
    references = "doi101038292239a0, doi101111j146979981983tb02087x, doi101126science493968, doi101152ajplegacy197021941104, doi101152jappl1963182367, doi101152jappl196722171, doi101242jeb1201297, doi101242jeb9711, doi1012490000576819850200000003, doi1023073700"
}

@article{baum1988bioenergetics,
    author = "Baum, Emanuel and Sterner, Sandra M.",
    title = "Bioenergetics",
    year = "1988",
    journal = "The Psychotherapy Patient",
    url = "https://doi.org/10.1300/j358v04n02\_12",
    doi = "10.1300/j358v04n02\_12",
    number = "2",
    pages = "123-133",
    volume = "4"
}

@incollection{nobel1991bioenergetics,
    author = "Nobel, Park S.",
    title = "Bioenergetics",
    year = "1991",
    booktitle = "Physicochemical and Plant Physiology",
    url = "https://doi.org/10.1016/b978-0-12-520020-2.50010-5",
    doi = "10.1016/b978-0-12-520020-2.50010-5",
    pages = "297-343"
}

We develop a general model for the effect of body size on fitness. We define fitness as reproductive power, the rate of conversion of energy into offspring. Reproductive power is assumed to be limited by a two-step process: first, the rate of acquisition of energy from the environment, which scales allometrically as body mass raised to approximately the 0.75 power, and then the rate of conversion of energy into offspring, which scales as mass to approximately the -0.25 power. The model predicts (1) the distinctive right-skewed shape of the frequency distribution of logarithms of body sizes among species that is observed in a wide variety of organisms from bacteria to mammals; (2) a taxon-specific optimal body size, which for mammals is approximately 100 g and is supported by data on the body sizes of mammals on islands; and (3) that in each taxon the relationships between such life-history and ecological characteristics as longevity, clutch size, home range size, and population density will change both slope and sign on either side of the optimal size. An energetic definition of fitness has the potential to unify areas of ecology and evolutionary biology that have previously used models based on different currencies.

@article{doi101086285558,
    author = "Brown, James H. and Marquet, Pablo A. and Taper, Mark L.",
    title = "Evolution of Body Size: Consequences of an Energetic Definition of Fitness",
    year = "1993",
    journal = "The American Naturalist",
    abstract = "We develop a general model for the effect of body size on fitness. We define fitness as reproductive power, the rate of conversion of energy into offspring. Reproductive power is assumed to be limited by a two-step process: first, the rate of acquisition of energy from the environment, which scales allometrically as body mass raised to approximately the 0.75 power, and then the rate of conversion of energy into offspring, which scales as mass to approximately the -0.25 power. The model predicts (1) the distinctive right-skewed shape of the frequency distribution of logarithms of body sizes among species that is observed in a wide variety of organisms from bacteria to mammals; (2) a taxon-specific optimal body size, which for mammals is approximately 100 g and is supported by data on the body sizes of mammals on islands; and (3) that in each taxon the relationships between such life-history and ecological characteristics as longevity, clutch size, home range size, and population density will change both slope and sign on either side of the optimal size. An energetic definition of fitness has the potential to unify areas of ecology and evolutionary biology that have previously used models based on different currencies.",
    url = "https://doi.org/10.1086/285558",
    doi = "10.1086/285558",
    openalex = "W2035571842",
    references = "doi101017cbo9780511608551, doi101038290699a0, doi101073pnas86147, doi101086282063, doi101086282637, doi101086284369, doi101086409052, doi101111j155856461973tb05912x, doi105860choice295104, openalexw1558456135, openalexw2080618944, openalexw2130289872"
}

Thermal optima for physiological processes are generally high (30°-40° C) in lizards. Performance decreases substantially at low temperatures, yet some lizards are nocturnal and are active with body temperatures below 15° C. We corroborated three hypotheses about the ecophysiological consequences of the evolution of nocturnality in lizards: (1) nocturnality requires activity at low temperature; (2) activity at low temperature imposes a thermal handicap that constrains performance capacity; (3) nocturnal species have higher performance capacity at low temperature than do comparable diurnal species. Field body temperatures during activity averaged 15.3°C in Teratoscincus przewalskii, a nocturnal, terrestrial gecko from northwestern China. Individuals of T. przewalskii sustained exercise at 15° C on a treadmill for more than 60 min at 0.18 km · h⁻¹. However, 15° C was suboptimal for sustained locomotion. Resting and maximum oxygen consumption at 15° and 25° C were similar to predicted values for diurnal lizards, supporting the hypothesis that much of thermal physiology in lizards is evolutionarily conservative. The minimum cost of transport (Cmin, 0.73 mL O₂ g⁻¹ km⁻¹) for T. przewalskii was only 34% of the predicted value for a diurnal lizard of the same mass. This low cost yielded a maximum aerobic speed (MAS) of 0.27 km · h⁻¹ at 15° C, which is 2.5 times the predicted MAS for a diurnal lizard of the same mass. In comparison with predicted values for diurnal lizards, T. przewalskii showed increased but thermally submaximal locomotor performance capacity at nighttime temperatures.

@article{doi101086physzool67130163845,
    author = "Autumn, Kellar and Weinstein, Randi B. and Full, Robert J.",
    title = "Low Cost of Locomotion Increases Performance at Low Temperature in a Nocturnal Lizard",
    year = "1994",
    journal = "Physiological Zoology",
    abstract = "Thermal optima for physiological processes are generally high (30°-40° C) in lizards. Performance decreases substantially at low temperatures, yet some lizards are nocturnal and are active with body temperatures below 15° C. We corroborated three hypotheses about the ecophysiological consequences of the evolution of nocturnality in lizards: (1) nocturnality requires activity at low temperature; (2) activity at low temperature imposes a thermal handicap that constrains performance capacity; (3) nocturnal species have higher performance capacity at low temperature than do comparable diurnal species. Field body temperatures during activity averaged 15.3°C in Teratoscincus przewalskii, a nocturnal, terrestrial gecko from northwestern China. Individuals of T. przewalskii sustained exercise at 15° C on a treadmill for more than 60 min at 0.18 km · h⁻¹. However, 15° C was suboptimal for sustained locomotion. Resting and maximum oxygen consumption at 15° and 25° C were similar to predicted values for diurnal lizards, supporting the hypothesis that much of thermal physiology in lizards is evolutionarily conservative. The minimum cost of transport (Cmin, 0.73 mL O₂ g⁻¹ km⁻¹) for T. przewalskii was only 34\% of the predicted value for a diurnal lizard of the same mass. This low cost yielded a maximum aerobic speed (MAS) of 0.27 km · h⁻¹ at 15° C, which is 2.5 times the predicted MAS for a diurnal lizard of the same mass. In comparison with predicted values for diurnal lizards, T. przewalskii showed increased but thermally submaximal locomotor performance capacity at nighttime temperatures.",
    url = "https://doi.org/10.1086/physzool.67.1.30163845",
    doi = "10.1086/physzool.67.1.30163845",
    openalex = "W2292338577",
    references = "doi101001jama194302840160064031, doi1010160169534789902115, doi101086284325, doi101093oso97801985464120010001, doi101093sysbio41118, doi101093sysbio423265, doi101152jappl1977421120, doi1023071437897, doi1023071948545, doi105860choice295104, full1987locomotion"
}

@article{skulachev1994bioenergetics,
    author = "Skulachev, Vladimir P.",
    title = "Bioenergetics: the evolution of molecular mechanisms and the development of bioenergetic concepts",
    year = "1994",
    journal = "Antonie van Leeuwenhoek",
    url = "https://doi.org/10.1007/bf00872213",
    doi = "10.1007/bf00872213",
    number = "4",
    openalex = "W2063219100",
    pages = "271-284",
    volume = "65",
    references = "doi1010079783642729782, doi1010160006300257903438, doi101016jbbabio201109018, doi101016s0021925818942304, doi101016s0022283605802712, doi101038191144a0, doi101038199222a0, doi101042bst0190608, doi101073pnas7473060, doi101111j1469185x1966tb01501x"
}

Bioenergetics is a very broad subject which covers a wide range of systems. The movement of electrons and ions across and through membranes is important in areas such as energy transduction, cell biology, and cell signalling. This book describes the core of bioenergetic techniques that are necessary to analyse membrane-translocating events.

@book{crossref1995bioenergetics,
    title = "Bioenergetics",
    year = "1995",
    abstract = "Bioenergetics is a very broad subject which covers a wide range of systems. The movement of electrons and ions across and through membranes is important in areas such as energy transduction, cell biology, and cell signalling. This book describes the core of bioenergetic techniques that are necessary to analyse membrane-translocating events.",
    url = "https://doi.org/10.1093/oso/9780199634897.001.0001",
    doi = "10.1093/oso/9780199634897.001.0001"
}

How viable is the argument that increased locomotor efficiency was an important agent in the origin of hominid bipedalism? This study reviews data from the literature on the cost of human bipedal walking and running and compares it to data on quadrupedal mammals including several non-human primate species. Literature data comparing the cost of bipedal and quadrupedal locomotion in trained capuchin monkeys and chimpanzees are also considered. It is concluded that increased energetic efficiency would not have accrued to early bipeds. Presumably, however, selection for improved efficiency in the bipedal stance would have occurred once the transition was made. Would such a process have included selection for increased limb length? Data on the cost of locomotion vs. limb length reveal no significant relationship between these variables in 21 species of mammals or in human walking or running.

@article{doi101002sici10968644199602992345aidajpa930co2x,
    author = "Steudel, Karen",
    title = "Limb morphology, bipedal gait, and the energetics of hominid locomotion",
    year = "1996",
    journal = "American Journal of Physical Anthropology",
    abstract = "How viable is the argument that increased locomotor efficiency was an important agent in the origin of hominid bipedalism? This study reviews data from the literature on the cost of human bipedal walking and running and compares it to data on quadrupedal mammals including several non-human primate species. Literature data comparing the cost of bipedal and quadrupedal locomotion in trained capuchin monkeys and chimpanzees are also considered. It is concluded that increased energetic efficiency would not have accrued to early bipeds. Presumably, however, selection for improved efficiency in the bipedal stance would have occurred once the transition was made. Would such a process have included selection for increased limb length? Data on the cost of locomotion vs. limb length reveal no significant relationship between these variables in 21 species of mammals or in human walking or running.",
    url = "https://doi.org/10.1002/(sici)1096-8644(199602)99:2<345::aid-ajpa9>3.0.co;2-x",
    doi = "10.1002/(sici)1096-8644(199602)99:2<345::aid-ajpa9>3.0.co;2-x",
    openalex = "W2041233973",
    references = "doi101002ajpa1330600302, doi101038292239a0, doi101038346265a0, doi101086284325, doi101093oso97801985464120010001, doi101093sysbio41118, doi101126science2114480341, doi101152ajpregu19772335r243, doi105860choice295104"
}

@incollection{nederkoorn1997bioenergetics,
    author = "Nederkoorn, Paul H. J. and Timmerman, Henk and den Kelder, Gabriëlle M. Donné-Op",
    title = "Bioenergetics",
    year = "1997",
    booktitle = "Molecular Biology Intelligence Unit",
    url = "https://doi.org/10.1007/978-1-4684-1407-3\_1",
    doi = "10.1007/978-1-4684-1407-3\_1",
    pages = "3-16"
}

ABSTRACT Although sauropods played a major role in terrestrial ecosystems during much of the Mesozoic Era, little effort has been directed toward diagnosing Sauropoda and establishing higher-level interrelationships among sauropods. As a consequence, the origin and evolution of major skeletal adaptations in sauropods has remained largely speculative. The cladistic analysis presented here focuses on higher-level relationships among sauropods. Based on 109 characters (32 cranial, 24 axial, 53 appendicular) for 10 sauropod taxa, the most parsimonious arrangement places four genera (Vulcanodon, Shunosaurus, Barapasaurus, and Omeisaurus) as a sequence of sister-taxa to a group of advanced sauropods, defined here as Neosauropoda. Neosauropoda, in turn, is composed of the sister-clades Diplodocoidea and Macronaria; the latter is a new taxon that includes Haplocanthosaurus, Camarasaurus, and Titanosauriformes. Titanosauriformes includes Brachiosauridae and Somphospondyli, a new taxon uniting Euhelopus and Titanosauria. Among macronarians, the position of Haplocanthosaurus is the least stable as a result of the absence of cranial remains. The basic structure of the phylogeny is resilient to various tests and establishes the evolutionary sequence of many functionally significant sauropod adaptations, such as the digitigrade posture of the manus in neosauropods. Other characteristic sauropod adaptations, such as narrow tooth crowns, increases in length and number of cervical vertebrae, and bifid neural spines, are shown to have evolved more than once. As these results underscore, the higher-level phylogeny of sauropods must be based on a broad sampling of character data. The fossil record of sauropods, although relatively limited during the early phase of the radiation (Late Triassic through Early Jurassic), nonetheless indicates that all major clades were established prior to the Late Jurassic, when substantial faunal interchange among major continental regions was still possible. The functional, temporal, and biogeographic implications of the higher-level phylogeny of sauropods are explored.

@article{doi10108002724634199810011115,
    author = "Wilson, Jeffrey A. and Sereno, Paul C.",
    title = "Early Evolution and Higher-Level Phylogeny of Sauropod Dinosaurs",
    year = "1998",
    journal = "Journal of Vertebrate Paleontology",
    abstract = "ABSTRACT Although sauropods played a major role in terrestrial ecosystems during much of the Mesozoic Era, little effort has been directed toward diagnosing Sauropoda and establishing higher-level interrelationships among sauropods. As a consequence, the origin and evolution of major skeletal adaptations in sauropods has remained largely speculative. The cladistic analysis presented here focuses on higher-level relationships among sauropods. Based on 109 characters (32 cranial, 24 axial, 53 appendicular) for 10 sauropod taxa, the most parsimonious arrangement places four genera (Vulcanodon, Shunosaurus, Barapasaurus, and Omeisaurus) as a sequence of sister-taxa to a group of advanced sauropods, defined here as Neosauropoda. Neosauropoda, in turn, is composed of the sister-clades Diplodocoidea and Macronaria; the latter is a new taxon that includes Haplocanthosaurus, Camarasaurus, and Titanosauriformes. Titanosauriformes includes Brachiosauridae and Somphospondyli, a new taxon uniting Euhelopus and Titanosauria. Among macronarians, the position of Haplocanthosaurus is the least stable as a result of the absence of cranial remains. The basic structure of the phylogeny is resilient to various tests and establishes the evolutionary sequence of many functionally significant sauropod adaptations, such as the digitigrade posture of the manus in neosauropods. Other characteristic sauropod adaptations, such as narrow tooth crowns, increases in length and number of cervical vertebrae, and bifid neural spines, are shown to have evolved more than once. As these results underscore, the higher-level phylogeny of sauropods must be based on a broad sampling of character data. The fossil record of sauropods, although relatively limited during the early phase of the radiation (Late Triassic through Early Jurassic), nonetheless indicates that all major clades were established prior to the Late Jurassic, when substantial faunal interchange among major continental regions was still possible. The functional, temporal, and biogeographic implications of the higher-level phylogeny of sauropods are explored.",
    url = "https://doi.org/10.1080/02724634.1998.10011115",
    doi = "10.1080/02724634.1998.10011115",
    openalex = "W1981694118",
    references = "crossref1976allosaurus, doi1010079789400904095, doi101038063003a0, doi101038114085a0, doi10108002724634199110011386, doi10108002724634199410011523, doi10108002724634199410011524, doi10108002724634199710011027, doi101093oxfordjournalsafrafa100309, doi101098rstb19950125, doi101111j109583121965tb00944x, doi101111j109636421985tb00871x, doi101111j150239311985tb00690x, doi101126science2562999, doi101126science2665183267, doi101127njgpa210199841, doi1023071292217, doi1023073514751, doi1023073514816, doi102307jctv143mdjg, doi102475ajss31695411, doi102475ajss319111253, doi102475ajss321125417, doi102475ajss32313381, doi105281zenodo16171435, doi105860choice331556, openalexw1025856234, openalexw2173200745, openalexw2472827083, openalexw616953834, openalexw653009579"
}

@incollection{stenesh1998bioenergetics,
    author = "Stenesh, J.",
    title = "Bioenergetics",
    year = "1998",
    booktitle = "Biochemistry",
    url = "https://doi.org/10.1007/978-1-4757-9427-4\_9",
    doi = "10.1007/978-1-4757-9427-4\_9",
    pages = "221-235"
}

Among local faunas, the maximum body size and taxonomic affiliation of the top terrestrial vertebrate vary greatly. Does this variation reflect how food requirements differ between trophic levels (herbivores vs. carnivores) and with taxonomic affiliation (mammals and birds vs. reptiles)? We gathered data on the body size and food requirements of the top terrestrial herbivores and carnivores, over the past 65,000 years, from oceanic islands and continents. The body mass of the top species was found to increase with increasing land area, with a slope similar to that of the relation between body mass and home range area, suggesting that maximum body size is determined by the number of home ranges that can fit into a given land area. For a given land area, the body size of the top species decreased in the sequence: ectothermic herbivore > endothermic herbivore > ectothermic carnivore > endothermic carnivore. When we converted body mass to food requirements, the food consumption of a top herbivore was about 8 times that of a top carnivore, in accord with the factor expected from the trophic pyramid. Although top ectotherms were heavier than top endotherms at a given trophic level, lower metabolic rates per gram of body mass in ectotherms resulted in endotherms and ectotherms having the same food consumption. These patterns explain the size of the largest-ever extinct mammal, but the size of the largest dinosaurs exceeds that predicted from land areas and remains unexplained.

@article{doi101073pnas251548698,
    author = "Burness, Gary and Diamond, Jared M. and Flannery, Timothy F.",
    title = "Dinosaurs, dragons, and dwarfs: The evolution of maximal body size",
    year = "2001",
    journal = "Proceedings of the National Academy of Sciences",
    abstract = "Among local faunas, the maximum body size and taxonomic affiliation of the top terrestrial vertebrate vary greatly. Does this variation reflect how food requirements differ between trophic levels (herbivores vs. carnivores) and with taxonomic affiliation (mammals and birds vs. reptiles)? We gathered data on the body size and food requirements of the top terrestrial herbivores and carnivores, over the past 65,000 years, from oceanic islands and continents. The body mass of the top species was found to increase with increasing land area, with a slope similar to that of the relation between body mass and home range area, suggesting that maximum body size is determined by the number of home ranges that can fit into a given land area. For a given land area, the body size of the top species decreased in the sequence: ectothermic herbivore > endothermic herbivore > ectothermic carnivore > endothermic carnivore. When we converted body mass to food requirements, the food consumption of a top herbivore was about 8 times that of a top carnivore, in accord with the factor expected from the trophic pyramid. Although top ectotherms were heavier than top endotherms at a given trophic level, lower metabolic rates per gram of body mass in ectotherms resulted in endotherms and ectotherms having the same food consumption. These patterns explain the size of the largest-ever extinct mammal, but the size of the largest dinosaurs exceeds that predicted from land areas and remains unexplained.",
    url = "https://doi.org/10.1073/pnas.251548698",
    doi = "10.1073/pnas.251548698",
    openalex = "W1974031613",
    references = "ciofi1999the, doi101016016953479090113r, doi101046j14698137199800221x, doi101086320621, doi1012019781420064452, doi101353book59141, doi1023072403875, doi102475ajs29910805, doi105860choice325665, doi105962bhltitle60647, doi107208chicago97802265867480010001"
}

Reconstructing the transition to bipedality is key to understanding early hominin evolution. Because it is the best-known early hominin species, Australopithecus afarensis forms a baseline for interpreting locomotion in all early hominins. While most researchers agree that A. afarensis individuals were habitual bipeds, they disagree over the importance of arboreality for them. There are two main reasons for the disagreement. First, there are divergent perspectives on how to interpret primitive characters. Primitive traits may be retained by stabilizing selection, pleiotropy, or other ontogenetic mechanisms. Alternately, they could be in the process of being reduced, or they simply could be selectively neutral. Second, researchers are asking fundamentally different questions about the fossils. Some are interested in reconstructing the history of selection that shaped A. afarensis, while others are interested in reconstructing A. afarensis behavior. By explicitly outlining whether we are interested in reconstructing selective history or behavior, we can develop testable hypotheses to govern our investigations of the fossils. To infer the selective history that shaped a taxon, we must first consider character polarity. Derived traits that enhance a particular function, are found to be associated with that function in extant homologs, and that epigenetically sensitive data indicate were actually being used for that function, can be interpreted as adaptations. The null hypothesis to explain the retention of primitive traits is that of selective neutrality, or nonaptation. Disproving this requires demonstration of active stabilizing or negative selection (disaptation). Stabilizing selection can be inferred when primitive traits compromise a derived function clearly of adaptive value. Prolonged stasis, continued use of the trait for a particular function, or no change in variability in the trait are evidence that can support a hypothesis of adaptation for primitive traits, but still do not falsify the null hypothesis. Disaptation, or negative selection, should result in a trait being reduced or lost. To infer the behaviors of a fossil species, we must first determine its adaptations, use this to make hypotheses about its behavior, and test these hypotheses using epigenetically sensitive traits that are modified by an individual's activity pattern. When the A. afarensis data are evaluated using this framework, it is clear that these hominins had undergone selection for habitual bipedality, but the null hypothesis of nonaptation to explain the retention of primitive, ape-like characters cannot be falsified at present. The apparent stasis in Australopithecus postcranial form is currently the strongest evidence for stabilizing selection maintaining its primitive features. Evidence from features affected by individual behaviors during ontogeny shows that A. afarensis individuals were habitually traveling bipedally, but evidence presented for arboreal behavior so far is not conclusive. By clearly identifying the questions we are asking about early hominin fossils, refining our knowledge about character polarities, and elucidating the factors influencing morphology, we will be able to progress in our understanding of the posture and locomotion of A. afarensis and all early hominins.

@article{doi101002ajpa10185,
    author = "Ward, Carol V.",
    title = "Interpreting the posture and locomotion ofAustralopithecus afarensis: Where do we stand?",
    year = "2002",
    journal = "American Journal of Physical Anthropology",
    abstract = "Reconstructing the transition to bipedality is key to understanding early hominin evolution. Because it is the best-known early hominin species, Australopithecus afarensis forms a baseline for interpreting locomotion in all early hominins. While most researchers agree that A. afarensis individuals were habitual bipeds, they disagree over the importance of arboreality for them. There are two main reasons for the disagreement. First, there are divergent perspectives on how to interpret primitive characters. Primitive traits may be retained by stabilizing selection, pleiotropy, or other ontogenetic mechanisms. Alternately, they could be in the process of being reduced, or they simply could be selectively neutral. Second, researchers are asking fundamentally different questions about the fossils. Some are interested in reconstructing the history of selection that shaped A. afarensis, while others are interested in reconstructing A. afarensis behavior. By explicitly outlining whether we are interested in reconstructing selective history or behavior, we can develop testable hypotheses to govern our investigations of the fossils. To infer the selective history that shaped a taxon, we must first consider character polarity. Derived traits that enhance a particular function, are found to be associated with that function in extant homologs, and that epigenetically sensitive data indicate were actually being used for that function, can be interpreted as adaptations. The null hypothesis to explain the retention of primitive traits is that of selective neutrality, or nonaptation. Disproving this requires demonstration of active stabilizing or negative selection (disaptation). Stabilizing selection can be inferred when primitive traits compromise a derived function clearly of adaptive value. Prolonged stasis, continued use of the trait for a particular function, or no change in variability in the trait are evidence that can support a hypothesis of adaptation for primitive traits, but still do not falsify the null hypothesis. Disaptation, or negative selection, should result in a trait being reduced or lost. To infer the behaviors of a fossil species, we must first determine its adaptations, use this to make hypotheses about its behavior, and test these hypotheses using epigenetically sensitive traits that are modified by an individual's activity pattern. When the A. afarensis data are evaluated using this framework, it is clear that these hominins had undergone selection for habitual bipedality, but the null hypothesis of nonaptation to explain the retention of primitive, ape-like characters cannot be falsified at present. The apparent stasis in Australopithecus postcranial form is currently the strongest evidence for stabilizing selection maintaining its primitive features. Evidence from features affected by individual behaviors during ontogeny shows that A. afarensis individuals were habitually traveling bipedally, but evidence presented for arboreal behavior so far is not conclusive. By clearly identifying the questions we are asking about early hominin fossils, refining our knowledge about character polarities, and elucidating the factors influencing morphology, we will be able to progress in our understanding of the posture and locomotion of A. afarensis and all early hominins.",
    url = "https://doi.org/10.1002/ajpa.10185",
    doi = "10.1002/ajpa.10185",
    openalex = "W2018595318",
    references = "doi10100215206505200093113aidevan230co2w, doi101002ajpa10011, doi101002ajpa10011abs, doi101002ajpa10019, doi101002ajpa10019abs, doi101002ajpa10021, doi101002ajpa1330380315, doi101002ajpa1330550203, doi101007bf02382954, doi101017s0031819100009189, doi101017s0094837300004310, doi101038248653a0, doi10108002724634199710011027, doi101086284325, doi101093icb232347, doi101093oso97801985464120010001, doi101098rspb19790086, doi101163156853980x00447, doi1015468p4gnhz, doi1023072405671, doi1023072800701, doi104324978131512740848, doi105281zenodo1038220, doi105860choice295104, doi105860choice326223, doi105860choice393984, doi107312simp93764, openalexw3098344224"
}

Wilson, Jeffrey A. (2002): Sauropod dinosaur phylogeny: critique and cladistic analysis. Zoological Journal of the Linnean Society 136 (2): 217-276, DOI: 10.1046/j.1096-3642.2002.00029.x, URL: https://academic.oup.com/zoolinnean/article-lookup/doi/10.1046/j.1096-3642.2002.00029.x

@article{doi101046j10963642200200029x,
    author = "Wilson, Jeffrey A.",
    title = "Sauropod dinosaur phylogeny: critique and cladistic analysis",
    year = "2002",
    journal = "Zoological Journal of the Linnean Society",
    abstract = "Wilson, Jeffrey A. (2002): Sauropod dinosaur phylogeny: critique and cladistic analysis. Zoological Journal of the Linnean Society 136 (2): 217-276, DOI: 10.1046/j.1096-3642.2002.00029.x, URL: https://academic.oup.com/zoolinnean/article-lookup/doi/10.1046/j.1096-3642.2002.00029.x",
    url = "https://doi.org/10.1046/j.1096-3642.2002.00029.x",
    doi = "10.1046/j.1096-3642.2002.00029.x",
    openalex = "W2018305891",
    references = "doi101002mmng19994860020102, doi101007978140206754912413, doi101017s0094837300026543, doi10108002724634199410011523, doi10108002724634199410011524, doi10108002724634199510011575, doi10108002724634199810011115, doi101098rstb19950125, doi101111j109636421998tb00569x, doi101111j155856461983tb05533x, doi101126science28053661048, doi101126science28454232137, doi101242dev1212333, doi1023071292217, doi1023072408332, doi1023072992353, doi102475ajss319111253, doi102475ajss321125417, doi102475ajss32313381, doi105281zenodo16171435, doi107312crac92306005, openalexw1025856234, openalexw3114518543, ostrom2019osteology"
}

1. Energetics of reproduction in birds is reviewed with the question in mind how the parent adjusts its effort in relation to prevailing environmental conditions in order to maximize the output of young in its lifetime. Emphasis is on proximate controls, rather than ultimate factors measurable in terms of adult survival and recruitment of young. 2. The decision to breed or not to breed is clearly related to body condition of the female, presumably because of the implications this has for survival. 3. Laying date and clutch size are likewise under the influence of female condition and can hence be modified by experiments involving supplementary feeding. Natural variation in these features may often be related to territory quality. 4. How the bird decides whether or not to commence a second brood is not clear, but in the Great Tit the habitat-related difference in incidence of second broods is functionally understandable when survival probabilities of birds at different times are considered. 5. A distinction is made between a capital and income model for translatting rates of change of female body condition into appropriate decisions on laying date and clutch size and experiments are suggested that discriminate between the two. 6. Lack's view that brood size is in an evolutionary sense adjusted in order to balance food requirement and foraging capacity of the parents is accepted, and growth rates in nidicolous birds are analysed to ascertain if a finer adjustment exists superimposed on the integer steps of brood adjustment. Critical for this analysis are groups of birds where broods of one are common, since only in these circumstances is growth adjustment the only strategy open to the parents. In common with other animals, growth rate is related to mature body size but within a category of adult weight clear examples can be found for retardation of growth rate in pelecaniform and charadriiform species with singleton broods. 7. Since daily energy requirement is related to nestling size and growth rate, retardation of growth is explicable as a strategy only in terms of reducing the daily commitment of the parents, not reducing the total cost of producing a nestling. 8. An additional economy in growth is to reduce the contribution of fat to the nestling body. 9. Implied in Lack's view of brood size is a limitation of parental foraging capacity, and the last section of the paper is devoted to exploration of the proximate factors delimiting what Royama terms the optimal working capacity of parents feeding young. Observations of parent starlings confronted with manipulated brood size suggest a limit on the time that can be devoted to energetically extravagant flight activity, rather than a shortage of absolute time. Beyond the limit to which stressed parents can be made to fly, body weight declines. 10. Preliminary data on energy metabolized daily by parents confronted with large broods conforms to the simplified view that parental effort on a sustained basis equates to energy mobilization equivalent to 4 B.M.R. units and it is suggested that this level of energy expenditure represents a proximal decision substrate for determining the optimal working capacity of the parent. 11. The paper ends with a plea for more research on the proximate controls of avian reproduction, and calls attention to the central importance of the protein bank to parental body condition.

@article{doi105253ardev68p225,
    author = "Drent, R.H. and Daan, Serge",
    title = "The Prudent Parent: Energetic Adjustments in Avian Breeding 1)",
    year = "2002",
    journal = "Ardea",
    abstract = "1. Energetics of reproduction in birds is reviewed with the question in mind how the parent adjusts its effort in relation to prevailing environmental conditions in order to maximize the output of young in its lifetime. Emphasis is on proximate controls, rather than ultimate factors measurable in terms of adult survival and recruitment of young. 2. The decision to breed or not to breed is clearly related to body condition of the female, presumably because of the implications this has for survival. 3. Laying date and clutch size are likewise under the influence of female condition and can hence be modified by experiments involving supplementary feeding. Natural variation in these features may often be related to territory quality. 4. How the bird decides whether or not to commence a second brood is not clear, but in the Great Tit the habitat-related difference in incidence of second broods is functionally understandable when survival probabilities of birds at different times are considered. 5. A distinction is made between a capital and income model for translatting rates of change of female body condition into appropriate decisions on laying date and clutch size and experiments are suggested that discriminate between the two. 6. Lack's view that brood size is in an evolutionary sense adjusted in order to balance food requirement and foraging capacity of the parents is accepted, and growth rates in nidicolous birds are analysed to ascertain if a finer adjustment exists superimposed on the integer steps of brood adjustment. Critical for this analysis are groups of birds where broods of one are common, since only in these circumstances is growth adjustment the only strategy open to the parents. In common with other animals, growth rate is related to mature body size but within a category of adult weight clear examples can be found for retardation of growth rate in pelecaniform and charadriiform species with singleton broods. 7. Since daily energy requirement is related to nestling size and growth rate, retardation of growth is explicable as a strategy only in terms of reducing the daily commitment of the parents, not reducing the total cost of producing a nestling. 8. An additional economy in growth is to reduce the contribution of fat to the nestling body. 9. Implied in Lack's view of brood size is a limitation of parental foraging capacity, and the last section of the paper is devoted to exploration of the proximate factors delimiting what Royama terms the optimal working capacity of parents feeding young. Observations of parent starlings confronted with manipulated brood size suggest a limit on the time that can be devoted to energetically extravagant flight activity, rather than a shortage of absolute time. Beyond the limit to which stressed parents can be made to fly, body weight declines. 10. Preliminary data on energy metabolized daily by parents confronted with large broods conforms to the simplified view that parental effort on a sustained basis equates to energy mobilization equivalent to 4 B.M.R. units and it is suggested that this level of energy expenditure represents a proximal decision substrate for determining the optimal working capacity of the parent. 11. The paper ends with a plea for more research on the proximate controls of avian reproduction, and calls attention to the central importance of the protein bank to parental body condition.",
    url = "https://doi.org/10.5253/arde.v68.p225",
    doi = "10.5253/arde.v68.p225",
    openalex = "W1682942551",
    references = "doi101007978134905226411, doi101021j150446a008, doi1023072828, doi1023072874"
}

The skeleton of Australopithecus afarensis (A.L. 288-1, better known as "Lucy") is by far the most complete record of locomotor morphology of early hominids currently available. Even though researchers agree that the postcranial skeleton of Lucy shows morphological features indicative of bipedality, only a few studies have investigated Lucy's bipedal locomotion itself. Lucy's energy expenditure during locomotion has been the topic of much speculation, but has not been investigated, except for several estimates derived from experimental data collected on other animals. To gain further insights into how Lucy may have walked, we generated a full three-dimensional (3D) reconstruction and forward-dynamic simulation of upright bipedal locomotion of this ancient human ancestor. Laser-scanned 3D bone geometries were combined with state-of-the-art neuromusculoskeletal modeling and simulation techniques from computational biomechanics. A detailed full 3D neuromusculoskeletal model was developed that encompassed all major bones, joints (10), and muscles (52) of the lower extremity. A model of muscle force and heat production was used to actuate the musculoskeletal system, and to estimate total energy expenditure during locomotion. Neural activation profiles for each of the 52 muscles that produced a single step of locomotion, while at the same time minimizing the energy consumed per meter traveled, were searched through numerical optimization. The numerical optimization resulted in smooth locomotor kinematics, and the predicted energy expenditure was appropriate for upright bipedal walking in an individual of Lucy's body size.

@article{doi101002ajpa10408,
    author = "Nagano, Akinori and Umberger, Brian R. and Marzke, Mary W. and Gerritsen, Karin G.M.",
    title = "Neuromusculoskeletal computer modeling and simulation of upright, straight‐legged, bipedal locomotion of Australopithecus afarensis (A.L. 288‐1)",
    year = "2004",
    journal = "American Journal of Physical Anthropology",
    abstract = {The skeleton of Australopithecus afarensis (A.L. 288-1, better known as "Lucy") is by far the most complete record of locomotor morphology of early hominids currently available. Even though researchers agree that the postcranial skeleton of Lucy shows morphological features indicative of bipedality, only a few studies have investigated Lucy's bipedal locomotion itself. Lucy's energy expenditure during locomotion has been the topic of much speculation, but has not been investigated, except for several estimates derived from experimental data collected on other animals. To gain further insights into how Lucy may have walked, we generated a full three-dimensional (3D) reconstruction and forward-dynamic simulation of upright bipedal locomotion of this ancient human ancestor. Laser-scanned 3D bone geometries were combined with state-of-the-art neuromusculoskeletal modeling and simulation techniques from computational biomechanics. A detailed full 3D neuromusculoskeletal model was developed that encompassed all major bones, joints (10), and muscles (52) of the lower extremity. A model of muscle force and heat production was used to actuate the musculoskeletal system, and to estimate total energy expenditure during locomotion. Neural activation profiles for each of the 52 muscles that produced a single step of locomotion, while at the same time minimizing the energy consumed per meter traveled, were searched through numerical optimization. The numerical optimization resulted in smooth locomotor kinematics, and the predicted energy expenditure was appropriate for upright bipedal walking in an individual of Lucy's body size.},
    url = "https://doi.org/10.1002/ajpa.10408",
    doi = "10.1002/ajpa.10408",
    openalex = "W2101110230",
    references = "doi101002ajpa1330600302, doi101002sici10968644199602992345aidajpa930co2x, doi1010160021929095001786, doi101016s0966636299000090, doi101038292239a0, doi101098rspb19380050, doi10111511336798, doi10111511392310, doi1021060000462319533503000003, doi105860choice282135, openalexw1506209475"
}

We review the evolution of human bipedal locomotion with a particular emphasis on the evolution of the foot. We begin in the early twentieth century and focus particularly on hypotheses of an ape-like ancestor for humans and human bipedal locomotion put forward by a succession of Gregory, Keith, Morton and Schultz. We give consideration to Morton's (1935) synthesis of foot evolution, in which he argues that the foot of the common ancestor of modern humans and the African apes would be intermediate between the foot of Pan and Hylobates whereas the foot of a hypothetical early hominin would be intermediate between that of a gorilla and a modern human. From this base rooted in comparative anatomy of living primates we trace changing ideas about the evolution of human bipedalism as increasing amounts of postcranial fossil material were discovered. Attention is given to the work of John Napier and John Robinson who were pioneers in the interpretation of Plio-Pleistocene hominin skeletons in the 1960s. This is the period when the wealth of evidence from the southern African australopithecine sites was beginning to be appreciated and Olduvai Gorge was revealing its first evidence for Homo habilis. In more recent years, the discovery of the Laetoli footprint trail, the AL 288-1 (A. afarensis) skeleton, the wealth of postcranial material from Koobi Fora, the Nariokotome Homo ergaster skeleton, Little Foot (Stw 573) from Sterkfontein in South Africa, and more recently tantalizing material assigned to the new and very early taxa Orrorin tugenensis, Ardipithecus ramidus and Sahelanthropus tchadensis has fuelled debate and speculation. The varying interpretations based on this material, together with changing theoretical insights and analytical approaches, is discussed and assessed in the context of new three-dimensional morphometric analyses of australopithecine and Homo foot bones, suggesting that there may have been greater diversity in human bipedalism in the earlier phases of our evolutionary history than previously suspected.

@article{doi101111j00218782200400296x,
    author = "Harcourt‐Smith, William E. H. and Aiello, Leslie C.",
    title = "Fossils, feet and the evolution of human bipedal locomotion",
    year = "2004",
    journal = "Journal of Anatomy",
    abstract = "We review the evolution of human bipedal locomotion with a particular emphasis on the evolution of the foot. We begin in the early twentieth century and focus particularly on hypotheses of an ape-like ancestor for humans and human bipedal locomotion put forward by a succession of Gregory, Keith, Morton and Schultz. We give consideration to Morton's (1935) synthesis of foot evolution, in which he argues that the foot of the common ancestor of modern humans and the African apes would be intermediate between the foot of Pan and Hylobates whereas the foot of a hypothetical early hominin would be intermediate between that of a gorilla and a modern human. From this base rooted in comparative anatomy of living primates we trace changing ideas about the evolution of human bipedalism as increasing amounts of postcranial fossil material were discovered. Attention is given to the work of John Napier and John Robinson who were pioneers in the interpretation of Plio-Pleistocene hominin skeletons in the 1960s. This is the period when the wealth of evidence from the southern African australopithecine sites was beginning to be appreciated and Olduvai Gorge was revealing its first evidence for Homo habilis. In more recent years, the discovery of the Laetoli footprint trail, the AL 288-1 (A. afarensis) skeleton, the wealth of postcranial material from Koobi Fora, the Nariokotome Homo ergaster skeleton, Little Foot (Stw 573) from Sterkfontein in South Africa, and more recently tantalizing material assigned to the new and very early taxa Orrorin tugenensis, Ardipithecus ramidus and Sahelanthropus tchadensis has fuelled debate and speculation. The varying interpretations based on this material, together with changing theoretical insights and analytical approaches, is discussed and assessed in the context of new three-dimensional morphometric analyses of australopithecine and Homo foot bones, suggesting that there may have been greater diversity in human bipedalism in the earlier phases of our evolutionary history than previously suspected.",
    url = "https://doi.org/10.1111/j.0021-8782.2004.00296.x",
    doi = "10.1111/j.0021-8782.2004.00296.x",
    openalex = "W2131226790",
    references = "doi10100215206505200093113aidevan230co2w, doi101002ajpa10019abs, doi101016b9780123840509500155, doi101038201969a0, doi101086397067, doi1023072800701"
}

This paper uses techniques from evolutionary robotics to predict the most energy-efficient upright walking gait for the early human relative Australopithecus afarensis, based on the proportions of the 3.2 million year old AL 288-1 'Lucy' skeleton, and matches predictions against the nearly contemporaneous (3.5-3.6 million year old) Laetoli fossil footprint trails. The technique creates gaits de novo and uses genetic algorithm optimization to search for the most efficient patterns of simulated muscular contraction at a variety of speeds. The model was first verified by predicting gaits for living human subjects, and comparing costs, stride lengths and speeds to experimentally determined values for the same subjects. Subsequent simulations for A. afarensis yield estimates of the range of walking speeds from 0.6 to 1.3 m s-1 at a cost of 7.0 J kg-1 m-1 for the lowest speeds, falling to 5.8 J kg-1 m-1 at 1.0 m s-1, and rising to 6.2 J kg-1 m-1 at the maximum speed achieved. Speeds previously estimated for the makers of the Laetoli footprint trails (0.56 or 0.64 m s-1 for Trail 1, 0.72 or 0.75 m s-1 for Trail 2/3) may have been underestimated, substantially so for Trail 2/3, with true values in excess of 0.7 and 1.0 m s-1, respectively. The predictions conflict with suggestions that A. afarensis used a 'shuffling' gait, indicating rather that the species was a fully competent biped.

@article{doi101098rsif20050060,
    author = "Sellers, William I. and Cain, Gemma M and Wang, Weijie and Crompton, Robin H.",
    title = "Stride lengths, speed and energy costs in walking of Australopithecus afarensis: using evolutionary robotics to predict locomotion of early human ancestors",
    year = "2005",
    journal = "Journal of The Royal Society Interface",
    abstract = "This paper uses techniques from evolutionary robotics to predict the most energy-efficient upright walking gait for the early human relative Australopithecus afarensis, based on the proportions of the 3.2 million year old AL 288-1 'Lucy' skeleton, and matches predictions against the nearly contemporaneous (3.5-3.6 million year old) Laetoli fossil footprint trails. The technique creates gaits de novo and uses genetic algorithm optimization to search for the most efficient patterns of simulated muscular contraction at a variety of speeds. The model was first verified by predicting gaits for living human subjects, and comparing costs, stride lengths and speeds to experimentally determined values for the same subjects. Subsequent simulations for A. afarensis yield estimates of the range of walking speeds from 0.6 to 1.3 m s-1 at a cost of 7.0 J kg-1 m-1 for the lowest speeds, falling to 5.8 J kg-1 m-1 at 1.0 m s-1, and rising to 6.2 J kg-1 m-1 at the maximum speed achieved. Speeds previously estimated for the makers of the Laetoli footprint trails (0.56 or 0.64 m s-1 for Trail 1, 0.72 or 0.75 m s-1 for Trail 2/3) may have been underestimated, substantially so for Trail 2/3, with true values in excess of 0.7 and 1.0 m s-1, respectively. The predictions conflict with suggestions that A. afarensis used a 'shuffling' gait, indicating rather that the species was a fully competent biped.",
    url = "https://doi.org/10.1098/rsif.2005.0060",
    doi = "10.1098/rsif.2005.0060",
    openalex = "W2097761913",
    references = "doi101002ajpa10408"
}

We hypothesized that the activation patterns of flexor and extensor muscles and the resulting kinematics of the forelimbs and hindlimbs during locomotion in the Rhesus would have unique characteristics relative to other quadrupedal mammals. Adaptations of limb movements and in motor pool recruitment patterns in accommodating a range of treadmill speeds similar to other terrestrial animals in both the hindlimb and forelimb were observed. Flexor and extensor motor neurons from motor pools in the lumbar segments, however, were more highly coordinated than in the cervical segments. Unlike the lateral sequence characterizing subprimate quadrupedal locomotion, non-human primates use diagonal coordination between the hindlimbs and forelimbs, similar to that observed in humans between the legs and arms. Although there was a high level of coordination between hind- and forelimb locomotion kinematics, limb-specific neural control strategies were evident in the intersegmental coordination patterns and limb endpoint trajectories. Based on limb kinematics and muscle recruitment patterns, it appears that the hindlimbs, and notably the distal extremities, contribute more to body propulsion than the forelimbs. Furthermore, we found adaptive changes in the recruitment patterns of distal muscles in the hind- and forelimb with increased treadmill speed that likely correlate with the anatomical and functional evolution of hand and foot digits in monkeys. Changes in the properties of both the spinal and supraspinal circuitry related to stepping, probably account for the peculiarities in the kinematic and EMG properties during non-human primate locomotion. We suggest that such adaptive changes may have facilitated evolution toward bipedal locomotion.

@article{doi101152jn010732004,
    author = "Courtine, Grégoire and Roy, Roland R. and Hodgson, John A. and McKay, Heather and Raven, Joseph and Zhong, Hui and Yang, Hong and Tuszynski, Mark H. and Edgerton, V. Reggie",
    title = "Kinematic and EMG Determinants in Quadrupedal Locomotion of a Non-Human Primate (Rhesus)",
    year = "2005",
    journal = "Journal of Neurophysiology",
    abstract = "We hypothesized that the activation patterns of flexor and extensor muscles and the resulting kinematics of the forelimbs and hindlimbs during locomotion in the Rhesus would have unique characteristics relative to other quadrupedal mammals. Adaptations of limb movements and in motor pool recruitment patterns in accommodating a range of treadmill speeds similar to other terrestrial animals in both the hindlimb and forelimb were observed. Flexor and extensor motor neurons from motor pools in the lumbar segments, however, were more highly coordinated than in the cervical segments. Unlike the lateral sequence characterizing subprimate quadrupedal locomotion, non-human primates use diagonal coordination between the hindlimbs and forelimbs, similar to that observed in humans between the legs and arms. Although there was a high level of coordination between hind- and forelimb locomotion kinematics, limb-specific neural control strategies were evident in the intersegmental coordination patterns and limb endpoint trajectories. Based on limb kinematics and muscle recruitment patterns, it appears that the hindlimbs, and notably the distal extremities, contribute more to body propulsion than the forelimbs. Furthermore, we found adaptive changes in the recruitment patterns of distal muscles in the hind- and forelimb with increased treadmill speed that likely correlate with the anatomical and functional evolution of hand and foot digits in monkeys. Changes in the properties of both the spinal and supraspinal circuitry related to stepping, probably account for the peculiarities in the kinematic and EMG properties during non-human primate locomotion. We suggest that such adaptive changes may have facilitated evolution toward bipedal locomotion.",
    url = "https://doi.org/10.1152/jn.01073.2004",
    doi = "10.1152/jn.01073.2004",
    openalex = "W2151838292",
    references = "doi101242jeb00279"
}

Cheetahs and beetles run, dolphins and salmon swim, and bees and birds fly with grace and economy surpassing our technology. Evolution has shaped the breathtaking abilities of animals, leaving us the challenge of reconstructing their targets of control and mechanisms of dexterity. In this review we explore a corner of this fascinating world. We describe mathematical models for legged animal locomotion, focusing on rapidly running insects, and highlighting achievements and challenges that remain. Newtonian body-limb dynamics are most naturally formulated as piecewise-holonomic rigid body mechanical systems, whose constraints change as legs touch down or lift off. Central pattern generators and proprioceptive sensing require models of spiking neurons, and simplified phase oscillator descriptions of ensembles of them. A full neuro-mechanical model of a running animal requires integration of these elements, along with proprioceptive feedback and models of goal-oriented sensing, planning and learning. We outline relevant background material from neurobiology and biomechanics, explain key properties of the hybrid dynamical systems that 1 underlie legged locomotion models, and provide numerous examples of such models, from the simplest, completely soluble ‘peg-leg walker ’ to complex neuro-muscular subsystems that are yet to be assembled into models of behaving animals. 1

@article{doi101137s0036144504445133,
    author = "Holmes, Philip and Full, Robert J. and Koditschek, Dan and Guckenheimer, John",
    title = "The Dynamics of Legged Locomotion: Models, Analyses, and Challenges",
    year = "2006",
    journal = "SIAM Review",
    abstract = "Cheetahs and beetles run, dolphins and salmon swim, and bees and birds fly with grace and economy surpassing our technology. Evolution has shaped the breathtaking abilities of animals, leaving us the challenge of reconstructing their targets of control and mechanisms of dexterity. In this review we explore a corner of this fascinating world. We describe mathematical models for legged animal locomotion, focusing on rapidly running insects, and highlighting achievements and challenges that remain. Newtonian body-limb dynamics are most naturally formulated as piecewise-holonomic rigid body mechanical systems, whose constraints change as legs touch down or lift off. Central pattern generators and proprioceptive sensing require models of spiking neurons, and simplified phase oscillator descriptions of ensembles of them. A full neuro-mechanical model of a running animal requires integration of these elements, along with proprioceptive feedback and models of goal-oriented sensing, planning and learning. We outline relevant background material from neurobiology and biomechanics, explain key properties of the hybrid dynamical systems that 1 underlie legged locomotion models, and provide numerous examples of such models, from the simplest, completely soluble ‘peg-leg walker ’ to complex neuro-muscular subsystems that are yet to be assembled into models of behaving animals. 1",
    url = "https://doi.org/10.1137/s0036144504445133",
    doi = "10.1137/s0036144504445133",
    openalex = "W1983815930",
    references = "doi101007bf00199436, doi101007bf01185408, doi101038292239a0, doi101086physzool67430163866, doi101111j146979981983tb04266x, doi101152ajpregu19772335r243, doi101242jeb1301155, doi101242jeb1381301, openalexw3081581194"
}

Based on our knowledge of locomotor biomechanics and ecology we predict the locomotion and posture of the last common ancestors of (a) great and lesser apes and their close fossil relatives (hominoids); (b) chimpanzees, bonobos and modern humans (hominines); and (c) modern humans and their fossil relatives (hominins). We evaluate our propositions against the fossil record in the context of a broader review of evolution of the locomotor system from the earliest hominoids of modern aspect (crown hominoids) to early modern Homo sapiens. While some early East African stem hominoids were pronograde, it appears that the adaptations which best characterize the crown hominoids are orthogrady and an ability to abduct the arm above the shoulder - rather than, as is often thought, manual suspension sensu stricto. At 7-9 Ma (not much earlier than the likely 4-8 Ma divergence date for panins and hominins, see Bradley, 2008) there were crown hominoids in southern Europe which were adapted to moving in an orthograde posture, supported primarily on the hindlimb, in an arboreal, and possibly for Oreopithecus, a terrestrial context. By 7 Ma, Sahelanthropus provides evidence of a Central African hominin, panin or possibly gorilline adapted to orthogrady, and both orthogrady and habitually highly extended postures of the hip are evident in the arboreal East African protohominin Orrorin at 6 Ma. If the traditional idea that hominins passed through a terrestrial 'knuckle-walking' phase is correct, not only does it have to be explained how a quadrupedal gait typified by flexed postures of the hindlimb could have preadapted the body for the hominin acquisition of straight-legged erect bipedality, but we would have to accept a transition from stem-hominoid pronogrady to crown hominoid orthogrady, back again to pronogrady in the African apes and then back to orthogrady in hominins. Hand-assisted arboreal bipedality, which is part of a continuum of orthograde behaviours, is used by modern orangutans to forage among the small branches at the periphery of trees where the core hominoid dietary resource, ripe fruit, is most often to be found. Derivation of habitual terrestrial bipedality from arboreal hand-assisted bipedality requires fewer transitions, and is also kinematically and kinetically more parsimonious.

@article{doi101111j14697580200800870x,
    author = "Crompton, Robin H. and Vereecke, E. E. and Thorpe, Susannah K. S.",
    title = "Locomotion and posture from the common hominoid ancestor to fully modern hominins, with special reference to the last common panin/hominin ancestor",
    year = "2008",
    journal = "Journal of Anatomy",
    abstract = "Based on our knowledge of locomotor biomechanics and ecology we predict the locomotion and posture of the last common ancestors of (a) great and lesser apes and their close fossil relatives (hominoids); (b) chimpanzees, bonobos and modern humans (hominines); and (c) modern humans and their fossil relatives (hominins). We evaluate our propositions against the fossil record in the context of a broader review of evolution of the locomotor system from the earliest hominoids of modern aspect (crown hominoids) to early modern Homo sapiens. While some early East African stem hominoids were pronograde, it appears that the adaptations which best characterize the crown hominoids are orthogrady and an ability to abduct the arm above the shoulder - rather than, as is often thought, manual suspension sensu stricto. At 7-9 Ma (not much earlier than the likely 4-8 Ma divergence date for panins and hominins, see Bradley, 2008) there were crown hominoids in southern Europe which were adapted to moving in an orthograde posture, supported primarily on the hindlimb, in an arboreal, and possibly for Oreopithecus, a terrestrial context. By 7 Ma, Sahelanthropus provides evidence of a Central African hominin, panin or possibly gorilline adapted to orthogrady, and both orthogrady and habitually highly extended postures of the hip are evident in the arboreal East African protohominin Orrorin at 6 Ma. If the traditional idea that hominins passed through a terrestrial 'knuckle-walking' phase is correct, not only does it have to be explained how a quadrupedal gait typified by flexed postures of the hindlimb could have preadapted the body for the hominin acquisition of straight-legged erect bipedality, but we would have to accept a transition from stem-hominoid pronogrady to crown hominoid orthogrady, back again to pronogrady in the African apes and then back to orthogrady in hominins. Hand-assisted arboreal bipedality, which is part of a continuum of orthograde behaviours, is used by modern orangutans to forage among the small branches at the periphery of trees where the core hominoid dietary resource, ripe fruit, is most often to be found. Derivation of habitual terrestrial bipedality from arboreal hand-assisted bipedality requires fewer transitions, and is also kinematically and kinetically more parsimonious.",
    url = "https://doi.org/10.1111/j.1469-7580.2008.00870.x",
    doi = "10.1111/j.1469-7580.2008.00870.x",
    openalex = "W2016925206",
    references = "doi101002ajpa10408, doi101016jjhevol200406002, doi101038201969a0, doi101073pnas0703267104, doi101242jeb00279"
}

The rise and diversification of the dinosaurs in the Late Triassic, from 230 to 200 million years ago, is a classic example of an evolutionary radiation with supposed competitive replacement. A comparison of evolutionary rates and morphological disparity of basal dinosaurs and their chief "competitors," the crurotarsan archosaurs, shows that dinosaurs exhibited lower disparity and an indistinguishable rate of character evolution. The radiation of Triassic archosaurs as a whole is characterized by declining evolutionary rates and increasing disparity, suggesting a decoupling of character evolution from body plan variety. The results strongly suggest that historical contingency, rather than prolonged competition or general "superiority," was the primary factor in the rise of dinosaurs.

@article{doi101126science1161833,
    author = "Brusatte, Stephen L. and Benton, Michael J. and Ruta, Marcello and Lloyd, Graeme T.",
    title = "Superiority, Competition, and Opportunism in the Evolutionary Radiation of Dinosaurs",
    year = "2008",
    journal = "Science",
    abstract = {The rise and diversification of the dinosaurs in the Late Triassic, from 230 to 200 million years ago, is a classic example of an evolutionary radiation with supposed competitive replacement. A comparison of evolutionary rates and morphological disparity of basal dinosaurs and their chief "competitors," the crurotarsan archosaurs, shows that dinosaurs exhibited lower disparity and an indistinguishable rate of character evolution. The radiation of Triassic archosaurs as a whole is characterized by declining evolutionary rates and increasing disparity, suggesting a decoupling of character evolution from body plan variety. The results strongly suggest that historical contingency, rather than prolonged competition or general "superiority," was the primary factor in the rise of dinosaurs.},
    url = "https://doi.org/10.1126/science.1161833",
    doi = "10.1126/science.1161833",
    openalex = "W2030637789",
    references = "benton1983dinosaur, doi101017s009483730001263x, doi101017s009483730001280x, doi101017s1477201907002040, doi101093oso97801985052350010001, doi101111j14754983200600614x, doi101111j155856461971tb01922x, doi101126science1065522, doi101126science1084786, doi101126science1143325, doi101126science2314734129, doi101126science28454232137, doi101126science28554321386, doi101525california97805202420980010001, doi1041599780674417922, doi105860choice396411"
}

Interpreting key ecological parameters, such as diet, of extinct organisms without the benefit of direct observation or explicit fossil evidence poses a formidable challenge for paleobiological studies. To date, dietary categorizations of extinct taxa are largely generated by means of modern analogs; however, for many species the method is subject to considerable ambiguity. Here we present a refined approach for assessing trophic habits in fossil taxa and apply the method to coelurosaurian dinosaurs--a clade for which diet is particularly controversial. Our findings detect 21 morphological features that exhibit statistically significant correlations with extrinsic fossil evidence of coelurosaurian herbivory, such as stomach contents and a gastric mill. These traits represent quantitative, extrinsically founded proxies for identifying herbivorous ecomorphology in fossils and are robust despite uncertainty in phylogenetic relationships among major coelurosaurian subclades. The distribution of these features suggests that herbivory was widespread among coelurosaurians, with six major subclades displaying morphological evidence of the diet, and that contrary to previous thought, hypercarnivory was relatively rare and potentially secondarily derived. Given the potential for repeated, independent evolution of herbivory in Coelurosauria, we also test for repetitive patterns in the appearance of herbivorous traits within sublineages using rank concordance analysis. We find evidence for a common succession of increasing specialization to herbivory in the subclades Ornithomimosauria and Oviraptorosauria, perhaps underlain by intrinsic functional and/or developmental constraints, as well as evidence indicating that the early evolution of a beak in coelurosaurians correlates with an herbivorous diet.

@article{doi101073pnas1011924108,
    author = "Zanno, Lindsay E. and Makovicky, Peter J.",
    title = "Herbivorous ecomorphology and specialization patterns in theropod dinosaur evolution",
    year = "2010",
    journal = "Proceedings of the National Academy of Sciences",
    abstract = "Interpreting key ecological parameters, such as diet, of extinct organisms without the benefit of direct observation or explicit fossil evidence poses a formidable challenge for paleobiological studies. To date, dietary categorizations of extinct taxa are largely generated by means of modern analogs; however, for many species the method is subject to considerable ambiguity. Here we present a refined approach for assessing trophic habits in fossil taxa and apply the method to coelurosaurian dinosaurs--a clade for which diet is particularly controversial. Our findings detect 21 morphological features that exhibit statistically significant correlations with extrinsic fossil evidence of coelurosaurian herbivory, such as stomach contents and a gastric mill. These traits represent quantitative, extrinsically founded proxies for identifying herbivorous ecomorphology in fossils and are robust despite uncertainty in phylogenetic relationships among major coelurosaurian subclades. The distribution of these features suggests that herbivory was widespread among coelurosaurians, with six major subclades displaying morphological evidence of the diet, and that contrary to previous thought, hypercarnivory was relatively rare and potentially secondarily derived. Given the potential for repeated, independent evolution of herbivory in Coelurosauria, we also test for repetitive patterns in the appearance of herbivorous traits within sublineages using rank concordance analysis. We find evidence for a common succession of increasing specialization to herbivory in the subclades Ornithomimosauria and Oviraptorosauria, perhaps underlain by intrinsic functional and/or developmental constraints, as well as evidence indicating that the early evolution of a beak in coelurosaurians correlates with an herbivorous diet.",
    url = "https://doi.org/10.1073/pnas.1011924108",
    doi = "10.1073/pnas.1011924108",
    openalex = "W2133829099",
    references = "doi10103831635, doi101038nature00930, doi101038nature08322, doi10108008912960600719988, doi101098rspb19940006, doi101111j1469185x201000137x, doi101126science1161833, doi101126science13334591105, doi101139e03011, doi101139e72031, doi101159000156416, doi1023072285423, doi105281zenodo1040385, doi105860choice326223, doi105860choice392183, openalexw2097385721, openalexw2611511275"
}

The herbivorous sauropod dinosaurs of the Jurassic and Cretaceous periods were the largest terrestrial animals ever, surpassing the largest herbivorous mammals by an order of magnitude in body mass. Several evolutionary lineages among Sauropoda produced giants with body masses in excess of 50 metric tonnes by conservative estimates. With body mass increase driven by the selective advantages of large body size, animal lineages will increase in body size until they reach the limit determined by the interplay of bauplan, biology, and resource availability. There is no evidence, however, that resource availability and global physicochemical parameters were different enough in the Mesozoic to have led to sauropod gigantism.

@article{doi101111j1469185x201000137x,
    author = "Sander, P. Martin and Christian, Andreas and Clauß, Marcus and Fechner, Regina and Gee, Carole T. and Griebeler, Eva-Maria and Gunga, Hanns‐Christian and Hummel, Jürgen and Mallison, Heinrich and Perry, Steven F. and Preuschoft, Holger and Rauhut, Oliver W. M. and Remes, Kristian and Tütken, Thomas and Wings, Oliver and Witzel, U.",
    title = "Biology of the sauropod dinosaurs: the evolution of gigantism",
    year = "2010",
    journal = "Biological reviews/Biological reviews of the Cambridge Philosophical Society",
    abstract = "The herbivorous sauropod dinosaurs of the Jurassic and Cretaceous periods were the largest terrestrial animals ever, surpassing the largest herbivorous mammals by an order of magnitude in body mass. Several evolutionary lineages among Sauropoda produced giants with body masses in excess of 50 metric tonnes by conservative estimates. With body mass increase driven by the selective advantages of large body size, animal lineages will increase in body size until they reach the limit determined by the interplay of bauplan, biology, and resource availability. There is no evidence, however, that resource availability and global physicochemical parameters were different enough in the Mesozoic to have led to sauropod gigantism.",
    url = "https://doi.org/10.1111/j.1469-185x.2010.00137.x",
    doi = "10.1111/j.1469-185x.2010.00137.x",
    openalex = "W2090710319",
    references = "amiot2006oxygen, christiansen2004mass, crossref1998encyclopedia, doi101002jez513, doi1010079789400904095, doi101016jpalaeo200901002, doi101016jtree200508012, doi101017cbo9780511565441, doi101017cbo9780511608551, doi101017cbo9781139167826, doi101017s0094837300009866, doi101017s0094837300021321, doi101017s1464793101005735, doi101021j150446a008, doi101038262207a0, doi101038344858a0, doi10103835086558, doi101046j10963642200200029x, doi101073pnas0708903105, doi101073pnas251548698, doi10108002724634199410011538, doi10108002724634199510011575, doi10108002724634199810011115, doi10108002724634199910011178, doi101098rsbl20070254, doi101098rspb20080715, doi101098rstb19950125, doi101111j109636421985tb00871x, doi101111j109636421998tb00569x, doi101111j146979981985tb04915x, doi101126science1118806, doi101139e93176, doi101146annurevecolsys36102003152631, doi101146annureves26110195002305, doi101242jeb029009, doi101371journalpone0001230, doi101371journalpone0006924, doi1015159781400881376, doi101525california97805202420980030015, doi101525california97805202420980030031, doi101525california97805202462320010001, doi1016660094837320000260466lhotts20co2, doi1016660094837320030290105dbttoo20co2, doi1016660094837320080340247ositlb20co2, doi1016710272463420000200115lbhoth20co2, doi1022179revmacn7344, doi1023072407154, doi1023073889325, doi102475ajss319111253, doi10560219780801881206, doi105860choice271523, doi105860choice304997, doi105860choice326223, doi105860choice353642, doi105860choice490282, martinsander2006bone, openalexw1025856234, openalexw114509570, openalexw1504554173, openalexw1534857865, openalexw1558456135, openalexw1585246501, openalexw1607828269, openalexw2318111898, openalexw2618301958, openalexw2983381470, openalexw3015256845, openalexw575222456, seymour1976dinosaurs"
}

Variation in daily activity patterns facilitates temporal partitioning of habitat and resources among species. Knowledge of temporal niche partitioning in paleobiological systems has been limited by the difficulty of obtaining reliable information about activity patterns from fossils. On the basis of an analysis of scleral ring and orbit morphology in 33 archosaurs, including dinosaurs and pterosaurs, we show that the eyes of Mesozoic archosaurs were adapted to all major types of diel activity (that is, nocturnal, diurnal, and cathemeral) and provide concrete evidence of temporal niche partitioning in the Mesozoic. Similar to extant amniotes, flyers were predominantly diurnal; terrestrial predators, at least partially, nocturnal; and large herbivores, cathemeral. These similarities suggest that ecology drives the evolution of diel activity patterns.

@article{doi101126science1200043,
    author = "Schmitz, Lars and Motani, Ryosuke",
    title = "Nocturnality in Dinosaurs Inferred from Scleral Ring and Orbit Morphology",
    year = "2011",
    journal = "Science",
    abstract = "Variation in daily activity patterns facilitates temporal partitioning of habitat and resources among species. Knowledge of temporal niche partitioning in paleobiological systems has been limited by the difficulty of obtaining reliable information about activity patterns from fossils. On the basis of an analysis of scleral ring and orbit morphology in 33 archosaurs, including dinosaurs and pterosaurs, we show that the eyes of Mesozoic archosaurs were adapted to all major types of diel activity (that is, nocturnal, diurnal, and cathemeral) and provide concrete evidence of temporal niche partitioning in the Mesozoic. Similar to extant amniotes, flyers were predominantly diurnal; terrestrial predators, at least partially, nocturnal; and large herbivores, cathemeral. These similarities suggest that ecology drives the evolution of diel activity patterns.",
    url = "https://doi.org/10.1126/science.1200043",
    doi = "10.1126/science.1200043",
    openalex = "W2072020803",
    references = "doi101016b9780123852502500183, doi101016jsedgeo200605013, doi101017cbo9780511565441, doi101034j1600048x2000310314x, doi101038272333a0, doi101111j1469185x1992tb01188x, doi101111j1469185x201000137x, doi101146annurevecolsys34011802132435, doi101525california97805202420980010001, doi1023071380998"
}

Despite the abundance of octapodal species and their evolutionary importance in originating terrestrial locomotion, the locomotion mechanics of spiders has received little attention so far. In this investigation we use inverse dynamics to study the locomotor performance of Grammostola mollicoma (18 g). Through 3-D kinematic measurements, the trajectory of the eight limbs and cephalothorax or abdomen allowed us to estimate the motion of the body centre of mass (COM) at different speeds. Classic mechanics of locomotion and multivariate analysis of several variables such as stride length and frequency, duty factor, mechanical external work and energy recovery, helped to identify two main gaits, a slow (speed <11 cm s(-1)) one and a fast one characterised by distinctive 3-D trajectories of COM. The total mechanical work (external + internal) calculated in the present study and metabolic data from the literature allowed us to estimate the locomotion efficiency of this species, which was less than 4%. Gait pattern due to alternating limb support, which generates asymmetrical COM trajectories and a small but consistent energy transfer between potential and kinetic energies of COM, is discussed both in terms of coordination indices and by referring to the octopod as formed by two quadrupeds in series. Analogies and differences of the newly obtained parameters with the allometric data and predictions are also illustrated.

@article{doi101242jeb057471,
    author = "Biancardi, Carlo M. and Fábrica, Gabriel and Polero, Patricia and Loss, Jefferson Fagundes and Minetti, Alberto E.",
    title = "Biomechanics of octopedal locomotion: kinematic and kinetic analysis of the spider Grammostola mollicoma",
    year = "2011",
    journal = "Journal of Experimental Biology",
    abstract = "Despite the abundance of octapodal species and their evolutionary importance in originating terrestrial locomotion, the locomotion mechanics of spiders has received little attention so far. In this investigation we use inverse dynamics to study the locomotor performance of Grammostola mollicoma (18 g). Through 3-D kinematic measurements, the trajectory of the eight limbs and cephalothorax or abdomen allowed us to estimate the motion of the body centre of mass (COM) at different speeds. Classic mechanics of locomotion and multivariate analysis of several variables such as stride length and frequency, duty factor, mechanical external work and energy recovery, helped to identify two main gaits, a slow (speed <11 cm s(-1)) one and a fast one characterised by distinctive 3-D trajectories of COM. The total mechanical work (external + internal) calculated in the present study and metabolic data from the literature allowed us to estimate the locomotion efficiency of this species, which was less than 4\%. Gait pattern due to alternating limb support, which generates asymmetrical COM trajectories and a small but consistent energy transfer between potential and kinetic energies of COM, is discussed both in terms of coordination indices and by referring to the octopod as formed by two quadrupeds in series. Analogies and differences of the newly obtained parameters with the allometric data and predictions are also illustrated.",
    url = "https://doi.org/10.1242/jeb.057471",
    doi = "10.1242/jeb.057471",
    openalex = "W2038240389",
    references = "doi101016002192909500017c, doi101016s0016699588800664, doi101109mex19864307016, doi101113jphysiol1976sp011613, doi101113jphysiol1977sp011866, doi101152physrev19896941199, doi101242jeb185171, doi1023071267831, doi1023073514548, full1987locomotion, openalexw2242001249"
}

List of Contributors Preface List of Institutional Abbreviations Introduction 1. Sauropod Biology and the Evolution of Gigantism: What Do We Know? / Marcus Clauss Part 1. Nutrition 2. Sauropod Feeding and Digestive Physiology / Jurgen Hummel and Marcus Clauss 3. Dietary Options for the Sauropod Dinosaurs from an Integrated Botanical and Paleobotanical Perspective / Carole T. Gee 4. The Diet of Sauropod Dinosaurs: Implications of Carbon Isotope Analysis on Teeth, Bones, and Plants / Thomas Tutken Part 2. Physiology 5. Structure and Function of the Sauropod Respiratory System / Steven F. Perry, Thomas Breuer, and Nadine Pajor 6. Reconstructing Body Volume and Surface Area of Dinosaurs Using Laser Scanning and Photogrammetry / Stefan Stoinski, Tim Suthau, and Hanns-Christian Gunga 7. Body Mass Estimation, Thermoregulation, and Cardiovascular Physiology of Large Sauropods / Bergita Ganse, Alexander Stahn, Stefan Stoinski, Tim Suthau, and Hanns-Christian Gunga Part 3. Construction 8. How to Get Big in the Mesozoic: The Evolution of the Sauropodomorph Body Plan / Oliver W. M. Rauhut, Regina Fechner, Kristian Remes, and Katrin Reis 9. Characterization of Sauropod Bone Structure / Maitena Dumont, Anke Pyzalla, Aleksander Kostka, and Andras Borbely 10. Finite Element Analyses and Virtual Syntheses of Biological Structures and Their Application to Sauropod Skulls / Ulrich Witzel, Julia Mannhardt, Rainer Goessling, Pascal de Micheli, and Holger Preuschoft 11. Walking with the Shoulder of Giants: Biomechanical Conditions in the Tetrapod Shoulder Girdle as a Basis for Sauropod Shoulder Reconstruction / Bianca Hohn 12. Why So Huge? Biomechanical Reasons for the Acquisition of Large Size in Sauropod and Theropod Dinosaurs / Holger Preuschoft, Bianca Hohn, Stefan Stoinski, and Ulrich Witzel 13. Plateosaurus in 3D: How CAD Models and Kinetic-Dynamic Modeling Bring an Extinct Animal to Life / Heinrich Mallison 14. Rearing Giants: Kinetic-Dynamic Modeling of Sauropod Bipedal and Tripodal Poses / Heinrich Mallison 15. Neck Posture in Sauropods / Andreas Christian and Gordon Dzemski Part 4. Growth 16. The Life Cycle of Sauropod Dinosaurs / Eva-Maria Griebeler and Jan Werner 17. Sauropod Bone Histology and Its Implications for Sauropod Biology / P. Martin Sander, Nicole Klein, Koen Stein, and Oliver Wings Part 5. Epilogue 18. Skeletal Reconstruction of Brachiosaurus brancai in the Museum fur Naturkunde, Berlin: Summarizing 70 Years of Sauropod Research / Kristian Remes, David M. Unwin, Nicole Klein, Wolf-Dieter Heinrich, and Oliver Hampe Appendix: Compilation of Published Body Mass Data for a Variety of Basal Sauropodomorphs and Sauropods Index

@article{doi105860choice490282,
    title = "Biology of the sauropod dinosaurs: understanding the life of giants",
    year = "2011",
    journal = "Choice Reviews Online",
    abstract = "List of Contributors Preface List of Institutional Abbreviations Introduction 1. Sauropod Biology and the Evolution of Gigantism: What Do We Know? / Marcus Clauss Part 1. Nutrition 2. Sauropod Feeding and Digestive Physiology / Jurgen Hummel and Marcus Clauss 3. Dietary Options for the Sauropod Dinosaurs from an Integrated Botanical and Paleobotanical Perspective / Carole T. Gee 4. The Diet of Sauropod Dinosaurs: Implications of Carbon Isotope Analysis on Teeth, Bones, and Plants / Thomas Tutken Part 2. Physiology 5. Structure and Function of the Sauropod Respiratory System / Steven F. Perry, Thomas Breuer, and Nadine Pajor 6. Reconstructing Body Volume and Surface Area of Dinosaurs Using Laser Scanning and Photogrammetry / Stefan Stoinski, Tim Suthau, and Hanns-Christian Gunga 7. Body Mass Estimation, Thermoregulation, and Cardiovascular Physiology of Large Sauropods / Bergita Ganse, Alexander Stahn, Stefan Stoinski, Tim Suthau, and Hanns-Christian Gunga Part 3. Construction 8. How to Get Big in the Mesozoic: The Evolution of the Sauropodomorph Body Plan / Oliver W. M. Rauhut, Regina Fechner, Kristian Remes, and Katrin Reis 9. Characterization of Sauropod Bone Structure / Maitena Dumont, Anke Pyzalla, Aleksander Kostka, and Andras Borbely 10. Finite Element Analyses and Virtual Syntheses of Biological Structures and Their Application to Sauropod Skulls / Ulrich Witzel, Julia Mannhardt, Rainer Goessling, Pascal de Micheli, and Holger Preuschoft 11. Walking with the Shoulder of Giants: Biomechanical Conditions in the Tetrapod Shoulder Girdle as a Basis for Sauropod Shoulder Reconstruction / Bianca Hohn 12. Why So Huge? Biomechanical Reasons for the Acquisition of Large Size in Sauropod and Theropod Dinosaurs / Holger Preuschoft, Bianca Hohn, Stefan Stoinski, and Ulrich Witzel 13. Plateosaurus in 3D: How CAD Models and Kinetic-Dynamic Modeling Bring an Extinct Animal to Life / Heinrich Mallison 14. Rearing Giants: Kinetic-Dynamic Modeling of Sauropod Bipedal and Tripodal Poses / Heinrich Mallison 15. Neck Posture in Sauropods / Andreas Christian and Gordon Dzemski Part 4. Growth 16. The Life Cycle of Sauropod Dinosaurs / Eva-Maria Griebeler and Jan Werner 17. Sauropod Bone Histology and Its Implications for Sauropod Biology / P. Martin Sander, Nicole Klein, Koen Stein, and Oliver Wings Part 5. Epilogue 18. Skeletal Reconstruction of Brachiosaurus brancai in the Museum fur Naturkunde, Berlin: Summarizing 70 Years of Sauropod Research / Kristian Remes, David M. Unwin, Nicole Klein, Wolf-Dieter Heinrich, and Oliver Hampe Appendix: Compilation of Published Body Mass Data for a Variety of Basal Sauropodomorphs and Sauropods Index",
    url = "https://doi.org/10.5860/choice.49-0282",
    doi = "10.5860/choice.49-0282",
    openalex = "W293512402",
    references = "amiot2006oxygen, christiansen2004mass, doi101002mmng200900004, doi1010160012825273900287, doi1010160031018275900279, doi1010160375650595000240, doi101016b9780126764604500081, doi101016jpalaeo200401006, doi101016jpalaeo200901002, doi101017cbo9780511608551, doi101017cbo9781139167826, doi101017s009483730000676x, doi101017s0094837300009866, doi101038229172a0, doi101038262207a0, doi10103835086558, doi101038nature00930, doi101038nature04633, doi101046j10963642200200029x, doi101073pnas251548698, doi101073pnas932514623, doi10108002724634199910011178, doi101111j1469185x201000137x, doi101111j146979981985tb04915x, doi101126science1138709, doi101242jeb02443, doi101525california97805202462320010001, doi1016660094837320000260734aaateo20co2, doi1016660094837320030290105dbttoo20co2, doi1016660094837320030290243vpasat20co2, doi1016660094837320080340247ositlb20co2, doi101666080251, doi1016710272463420020220766tehits20co2, doi1023071310735, doi1023073515313, doi104039ent912935, doi105860choice271523, doi105860choice324505, doi105962bhltitle118957, martinsander2006bone, openalexw1534857865, openalexw1558456135, openalexw1590241584, openalexw2473973115, openalexw2729191089, openalexw603337959, seymour1976dinosaurs"
}

The study of phenotypic evolution should be an integrative endeavor that combines different approaches and crosses disciplinary and phylogenetic boundaries to consider complex traits and organisms that historically have been studied in isolation from each other. Analyses of individual variation within populations can act to bridge studies focused at the levels of morphology, physiology, biochemistry, organismal performance, behavior, and life history. For example, the study of individual variation recently facilitated the integration of behavior into the concept of a pace-of-life syndrome and effectively linked the field of energetics with research on animal personality. Here, we illustrate how studies on the pace-of-life syndrome and the energetics of personality can be integrated within a physiology-performance-behavior-fitness paradigm that includes consideration of ecological context. We first introduce key concepts and definitions and then review the rapidly expanding literature on the links between energy metabolism and personality traits commonly studied in nonhuman animals (activity, exploration, boldness, aggressiveness, sociability). We highlight some empirical literature involving mammals and squamates that demonstrates how emerging fields can develop in rather disparate ways because of historical accidents and/or particularities of different kinds of organisms. We then briefly discuss potentially interesting avenues for future conceptual and empirical research in relation to motivation, intraindividual variation, and mechanisms underlying trait correlations. The integration of performance traits within the pace-of-life-syndrome concept has the potential to fill a logical gap between the context dependency of selection and how energetics and personality are expected to interrelate. Studies of how performance abilities and/or aspects of Darwinian fitness relate to both metabolic rate and personality traits are particularly lacking.

@article{doi101086666970,
    author = "Careau, Vincent and Garland, Theodore",
    title = "Performance, Personality, and Energetics: Correlation, Causation, and Mechanism",
    year = "2012",
    journal = "Physiological and Biochemical Zoology",
    abstract = "The study of phenotypic evolution should be an integrative endeavor that combines different approaches and crosses disciplinary and phylogenetic boundaries to consider complex traits and organisms that historically have been studied in isolation from each other. Analyses of individual variation within populations can act to bridge studies focused at the levels of morphology, physiology, biochemistry, organismal performance, behavior, and life history. For example, the study of individual variation recently facilitated the integration of behavior into the concept of a pace-of-life syndrome and effectively linked the field of energetics with research on animal personality. Here, we illustrate how studies on the pace-of-life syndrome and the energetics of personality can be integrated within a physiology-performance-behavior-fitness paradigm that includes consideration of ecological context. We first introduce key concepts and definitions and then review the rapidly expanding literature on the links between energy metabolism and personality traits commonly studied in nonhuman animals (activity, exploration, boldness, aggressiveness, sociability). We highlight some empirical literature involving mammals and squamates that demonstrates how emerging fields can develop in rather disparate ways because of historical accidents and/or particularities of different kinds of organisms. We then briefly discuss potentially interesting avenues for future conceptual and empirical research in relation to motivation, intraindividual variation, and mechanisms underlying trait correlations. The integration of performance traits within the pace-of-life-syndrome concept has the potential to fill a logical gap between the context dependency of selection and how energetics and personality are expected to interrelate. Studies of how performance abilities and/or aspects of Darwinian fitness relate to both metabolic rate and personality traits are particularly lacking.",
    url = "https://doi.org/10.1086/666970",
    doi = "10.1086/666970",
    openalex = "W1985062481",
    references = "doi101111j1365294x200904427x, doi101126science493968, doi101242jeb01553"
}

In our reconstructions of human evolution, a few key questions consistently rise to the surface. These questions tend to revolve around how the morphology of previous hominin species would have allowed them to gain access to resources during key life-history events, particularly gestation and lactation. Here the data surrounding the interactions between these key issues are assessed, making particular notes of recent advances in the fields of energetics and biomechanics as they relate to locomotion during reproduction. Reconstructions of body mass, lower limb length, and pelvic breadth suggest diverse mobility strategies for different hominin species and may offer some clues about the demographic shifts occurring in the late Pleistocene.

@article{wallscheffler2012energetics,
    author = "Wall-Scheffler, Cara M.",
    title = "Energetics, Locomotion, and Female Reproduction: Implications for Human Evolution",
    year = "2012",
    journal = "Annual Review of Anthropology",
    abstract = "In our reconstructions of human evolution, a few key questions consistently rise to the surface. These questions tend to revolve around how the morphology of previous hominin species would have allowed them to gain access to resources during key life-history events, particularly gestation and lactation. Here the data surrounding the interactions between these key issues are assessed, making particular notes of recent advances in the fields of energetics and biomechanics as they relate to locomotion during reproduction. Reconstructions of body mass, lower limb length, and pelvic breadth suggest diverse mobility strategies for different hominin species and may offer some clues about the demographic shifts occurring in the late Pleistocene.",
    url = "https://doi.org/10.1146/annurev-anthro-092611-145739",
    doi = "10.1146/annurev-anthro-092611-145739",
    number = "1",
    openalex = "W2098329679",
    pages = "71-85",
    volume = "41",
    references = "doi101002ajhb10152, doi101002ajpa1330370605, doi101007bf00167814, doi101007bf00698754, doi101016jjbiomech200306002, doi10103712293000, doi101038nature03052, doi101038scientificamerican1188118, doi1010970000367720050400000006, doi1023072802232"
}

@misc{crossref2013bioenergetics,
    title = "Bioenergetics",
    year = "2013",
    url = "https://doi.org/10.1016/c2010-0-64902-9",
    doi = "10.1016/c2010-0-64902-9"
}

Digestive physiology has played a prominent role in explanations for terrestrial herbivore body size evolution and size-driven diversification and niche differentiation. This is based on the association of increasing body mass (BM) with diets of lower quality, and with putative mechanisms by which a higher BM could translate into a higher digestive efficiency. Such concepts, however, often do not match empirical data. Here, we review concepts and data on terrestrial herbivore BM, diet quality, digestive physiology and metabolism, and in doing so give examples for problems in using allometric analyses and extrapolations. A digestive advantage of larger BM is not corroborated by conceptual or empirical approaches. We suggest that explanatory models should shift from physiological to ecological scenarios based on the association of forage quality and biomass availability, and the association between BM and feeding selectivity. These associations mostly (but not exclusively) allow large herbivores to use low quality forage only, whereas they allow small herbivores the use of any forage they can physically manage. Examples of small herbivores able to subsist on lower quality diets are rare but exist. We speculate that this could be explained by evolutionary adaptations to the ecological opportunity of selective feeding in smaller animals, rather than by a physiologic or metabolic necessity linked to BM. For gigantic herbivores such as sauropod dinosaurs, other factors than digestive physiology appear more promising candidates to explain evolutionary drives towards extreme BM.

@article{doi101371journalpone0068714,
    author = "Clauß, Marcus and Steuer, Patrick and Müller, Dennis and Codron, Daryl and Hummel, Jürgen",
    title = "Herbivory and Body Size: Allometries of Diet Quality and Gastrointestinal Physiology, and Implications for Herbivore Ecology and Dinosaur Gigantism",
    year = "2013",
    journal = "PLoS ONE",
    abstract = "Digestive physiology has played a prominent role in explanations for terrestrial herbivore body size evolution and size-driven diversification and niche differentiation. This is based on the association of increasing body mass (BM) with diets of lower quality, and with putative mechanisms by which a higher BM could translate into a higher digestive efficiency. Such concepts, however, often do not match empirical data. Here, we review concepts and data on terrestrial herbivore BM, diet quality, digestive physiology and metabolism, and in doing so give examples for problems in using allometric analyses and extrapolations. A digestive advantage of larger BM is not corroborated by conceptual or empirical approaches. We suggest that explanatory models should shift from physiological to ecological scenarios based on the association of forage quality and biomass availability, and the association between BM and feeding selectivity. These associations mostly (but not exclusively) allow large herbivores to use low quality forage only, whereas they allow small herbivores the use of any forage they can physically manage. Examples of small herbivores able to subsist on lower quality diets are rare but exist. We speculate that this could be explained by evolutionary adaptations to the ecological opportunity of selective feeding in smaller animals, rather than by a physiologic or metabolic necessity linked to BM. For gigantic herbivores such as sauropod dinosaurs, other factors than digestive physiology appear more promising candidates to explain evolutionary drives towards extreme BM.",
    url = "https://doi.org/10.1371/journal.pone.0068714",
    doi = "10.1371/journal.pone.0068714",
    openalex = "W2034817348",
    references = "doi101016c20130113815, doi101017cbo9780511565441, doi10103846266, doi101086284369, doi101086284385, doi101098rspb20122526, doi101111j1469185x201000137x, doi1023071938809, doi1023072259478, doi105860choice324505, doi1075919781501732355"
}

BACKGROUND: Tooth replacement rate can be calculated in extinct animals by counting incremental lines of deposition in tooth dentin. Calculating this rate in several taxa allows for the study of the evolution of tooth replacement rate. Sauropod dinosaurs, the largest terrestrial animals that ever evolved, exhibited a diversity of tooth sizes and shapes, but little is known about their tooth replacement rates. METHODOLOGY/PRINCIPAL FINDINGS: We present tooth replacement rate, formation time, crown volume, total dentition volume, and enamel thickness for two coexisting but distantly related and morphologically disparate sauropod dinosaurs Camarasaurus and Diplodocus. Individual tooth formation time was determined by counting daily incremental lines in dentin. Tooth replacement rate is calculated as the difference between the number of days recorded in successive replacement teeth. Each tooth family in Camarasaurus has a maximum of three replacement teeth, whereas each Diplodocus tooth family has up to five. Tooth formation times are about 1.7 times longer in Camarasaurus than in Diplodocus (315 vs. 185 days). Average tooth replacement rate in Camarasaurus is about one tooth every 62 days versus about one tooth every 35 days in Diplodocus. Despite slower tooth replacement rates in Camarasaurus, the volumetric rate of Camarasaurus tooth replacement is 10 times faster than in Diplodocus because of its substantially greater tooth volumes. A novel method to estimate replacement rate was developed and applied to several other sauropodomorphs that we were not able to thin section. CONCLUSIONS/SIGNIFICANCE: Differences in tooth replacement rate among sauropodomorphs likely reflect disparate feeding strategies and/or food choices, which would have facilitated the coexistence of these gigantic herbivores in one ecosystem. Early neosauropods are characterized by high tooth replacement rates (despite their large tooth size), and derived titanosaurs and diplodocoids independently evolved the highest known tooth replacement rates among archosaurs.

@article{doi101371journalpone0069235,
    author = "D’Emic, Michael D. and Whitlock, John A. and Smith, Kathlyn M. and Fisher, Daniel C. and Wilson, Jeffrey A.",
    title = "Evolution of High Tooth Replacement Rates in Sauropod Dinosaurs",
    year = "2013",
    journal = "PLoS ONE",
    abstract = "BACKGROUND: Tooth replacement rate can be calculated in extinct animals by counting incremental lines of deposition in tooth dentin. Calculating this rate in several taxa allows for the study of the evolution of tooth replacement rate. Sauropod dinosaurs, the largest terrestrial animals that ever evolved, exhibited a diversity of tooth sizes and shapes, but little is known about their tooth replacement rates. METHODOLOGY/PRINCIPAL FINDINGS: We present tooth replacement rate, formation time, crown volume, total dentition volume, and enamel thickness for two coexisting but distantly related and morphologically disparate sauropod dinosaurs Camarasaurus and Diplodocus. Individual tooth formation time was determined by counting daily incremental lines in dentin. Tooth replacement rate is calculated as the difference between the number of days recorded in successive replacement teeth. Each tooth family in Camarasaurus has a maximum of three replacement teeth, whereas each Diplodocus tooth family has up to five. Tooth formation times are about 1.7 times longer in Camarasaurus than in Diplodocus (315 vs. 185 days). Average tooth replacement rate in Camarasaurus is about one tooth every 62 days versus about one tooth every 35 days in Diplodocus. Despite slower tooth replacement rates in Camarasaurus, the volumetric rate of Camarasaurus tooth replacement is 10 times faster than in Diplodocus because of its substantially greater tooth volumes. A novel method to estimate replacement rate was developed and applied to several other sauropodomorphs that we were not able to thin section. CONCLUSIONS/SIGNIFICANCE: Differences in tooth replacement rate among sauropodomorphs likely reflect disparate feeding strategies and/or food choices, which would have facilitated the coexistence of these gigantic herbivores in one ecosystem. Early neosauropods are characterized by high tooth replacement rates (despite their large tooth size), and derived titanosaurs and diplodocoids independently evolved the highest known tooth replacement rates among archosaurs.",
    url = "https://doi.org/10.1371/journal.pone.0069235",
    doi = "10.1371/journal.pone.0069235",
    openalex = "W2041856039",
    references = "doi105860choice490282, openalexw2786463731"
}

@article{doi101016jcub201408034,
    author = "Brusatte, Stephen L. and Lloyd, Graeme T. and Wang, Steve C. and Norell, Mark A.",
    title = "Gradual Assembly of Avian Body Plan Culminated in Rapid Rates of Evolution across the Dinosaur-Bird Transition",
    year = "2014",
    journal = "Current Biology",
    url = "https://doi.org/10.1016/j.cub.2014.08.034",
    doi = "10.1016/j.cub.2014.08.034",
    openalex = "W2000971221",
    references = "crossref1976allosaurus, doi10100703064746897, doi101007s001140090614x, doi101016jcretres201103005, doi101016jearscirev201004001, doi101016jjafrearsci201205005, doi101017s0006323197005100, doi101017s009483730001263x, doi10103832884, doi10103835086558, doi101038378774a0, doi101038nature02855, doi101038nature03996, doi101038nature04511, doi101038nature07447, doi101038nature10288, doi101038nature10906, doi101038nature12168, doi101038ncomms1815, doi101073pnas1006970107, doi101080027246342010520779, doi101093aesa383396, doi101111evo12150, doi101111j10960031200700161x, doi101111j10960031200800217x, doi101111j10963642200900571x, doi101111j14209101201002039x, doi101111j1469185x1997tb00024x, doi101111j14697580200600534x, doi101111j15585646201001025x, doi101111j2041210x201100169x, doi101111j2041210x201200223x, doi101126science1144066, doi101126science1161833, doi101126science1193304, doi101126science1252243, doi101144sp31516, doi10120600030082200635451andtfu20co2, doi1012067481, doi101371journalpbio1001853, doi101371journalpone0031838, doi1022179revmacn14372, doi1022179revmacn8325, doi105281zenodo16171435, doi105281zenodo16651680, openalexw2183707334"
}

Titanosaurian sauropod dinosaurs were the most diverse and abundant large-bodied herbivores in the southern continents during the final 30 million years of the Mesozoic Era. Several titanosaur species are regarded as the most massive land-living animals yet discovered; nevertheless, nearly all of these giant titanosaurs are known only from very incomplete fossils, hindering a detailed understanding of their anatomy. Here we describe a new and gigantic titanosaur, Dreadnoughtus schrani, from Upper Cretaceous sediments in southern Patagonia, Argentina. Represented by approximately 70% of the postcranial skeleton, plus craniodental remains, Dreadnoughtus is the most complete giant titanosaur yet discovered, and provides new insight into the morphology and evolutionary history of these colossal animals. Furthermore, despite its estimated mass of about 59.3 metric tons, the bone histology of the Dreadnoughtus type specimen reveals that this individual was still growing at the time of death.

@article{doi101038srep06196,
    author = "Lacovara, Kenneth J. and Lamanna, Matthew C. and Ibiricu, Lucio M. and Poole, Jason C. and Schroeter, Elena R. and Ullmann, Paul V. and Voegele, Kristyn K. and Boles, Zachary M. and Carter, Aja M. and Fowler, Emma K. and Egerton, Victoria M. and Moyer, Alison E. and Coughenour, Christopher and Schein, Jason P. and Harris, Jerald D. and Martínez, Rubén D. and Novas, Fernando E.",
    title = "A Gigantic, Exceptionally Complete Titanosaurian Sauropod Dinosaur from Southern Patagonia, Argentina",
    year = "2014",
    journal = "Scientific Reports",
    abstract = "Titanosaurian sauropod dinosaurs were the most diverse and abundant large-bodied herbivores in the southern continents during the final 30 million years of the Mesozoic Era. Several titanosaur species are regarded as the most massive land-living animals yet discovered; nevertheless, nearly all of these giant titanosaurs are known only from very incomplete fossils, hindering a detailed understanding of their anatomy. Here we describe a new and gigantic titanosaur, Dreadnoughtus schrani, from Upper Cretaceous sediments in southern Patagonia, Argentina. Represented by approximately 70\% of the postcranial skeleton, plus craniodental remains, Dreadnoughtus is the most complete giant titanosaur yet discovered, and provides new insight into the morphology and evolutionary history of these colossal animals. Furthermore, despite its estimated mass of about 59.3 metric tons, the bone histology of the Dreadnoughtus type specimen reveals that this individual was still growing at the time of death.",
    url = "https://doi.org/10.1038/srep06196",
    doi = "10.1038/srep06196",
    openalex = "W2025269251",
    references = "doi101046j10963642200200029x, doi101073pnas251548698, doi101111j10960031200800217x, doi101111j109636421998tb00569x, doi101111j1469185x201000137x, doi101111j146979981985tb04915x, doi101111zoj12029, doi101186174170071060, doi101371journalpbio1001853, doi101371journalpone0006190, doi101371journalpone0017114, doi1016660094837320080340247ositlb20co2, doi1022179revmacn12239, doi1022179revmacn688, doi1022179revmacn7344, openalexw581267017"
}

Herbivorous dinosaurs were abundant, species-rich components of Late Triassic–Cretaceous terrestrial ecosystems. Obligate high-fiber herbivory evolved independently on several occasions within Dinosauria, through the intermediary step of omnivory. Anatomical character complexes associated with this diet exhibit high levels of convergence and morphological disparity, and may have evolved by correlated progression. Dinosaur faunas changed markedly during the Mesozoic, from early faunas dominated by taxa with simple, uniform feeding mechanics to Cretaceous biomes including diverse sophisticated sympatric herbivores; the environmental and biological drivers causing these changes remain unclear. Isotopic, taphonomic, and anatomical evidence implies that niche partitioning reduced competition between sympatric herbivores, via morphological differentiation, dietary preferences, and habitat selection. Large body size in dinosaur herbivores is associated with low plant productivity, and gave these animals prominent roles as ecosystem engineers. Although dinosaur herbivores lived through several major events in floral evolution, there is currently no evidence for plant-dinosaur coevolutionary interactions.

@article{doi101146annurevearth042711105515,
    author = "Barrett, Paul M.",
    title = "Paleobiology of Herbivorous Dinosaurs",
    year = "2014",
    journal = "Annual Review of Earth and Planetary Sciences",
    abstract = "Herbivorous dinosaurs were abundant, species-rich components of Late Triassic–Cretaceous terrestrial ecosystems. Obligate high-fiber herbivory evolved independently on several occasions within Dinosauria, through the intermediary step of omnivory. Anatomical character complexes associated with this diet exhibit high levels of convergence and morphological disparity, and may have evolved by correlated progression. Dinosaur faunas changed markedly during the Mesozoic, from early faunas dominated by taxa with simple, uniform feeding mechanics to Cretaceous biomes including diverse sophisticated sympatric herbivores; the environmental and biological drivers causing these changes remain unclear. Isotopic, taphonomic, and anatomical evidence implies that niche partitioning reduced competition between sympatric herbivores, via morphological differentiation, dietary preferences, and habitat selection. Large body size in dinosaur herbivores is associated with low plant productivity, and gave these animals prominent roles as ecosystem engineers. Although dinosaur herbivores lived through several major events in floral evolution, there is currently no evidence for plant-dinosaur coevolutionary interactions.",
    url = "https://doi.org/10.1146/annurev-earth-042711-105515",
    doi = "10.1146/annurev-earth-042711-105515",
    openalex = "W2127568739",
    references = "doi10100797836426953391, doi101007s0001501000206, doi101016jpalaeo201206024, doi101016jpalaeo201206027, doi101038ncomms1815, doi101111j14209101201102427x, doi101111j150239311985tb00690x, doi101146annureves26110195002305, doi101186147267851314, doi101371journalpone0012553, doi101371journalpone0067182, doi105860choice490282, openalexw2971401580"
}

Large-scale adaptive radiations might explain the runaway success of a minority of extant vertebrate clades. This hypothesis predicts, among other things, rapid rates of morphological evolution during the early history of major groups, as lineages invade disparate ecological niches. However, few studies of adaptive radiation have included deep time data, so the links between extant diversity and major extinct radiations are unclear. The intensively studied Mesozoic dinosaur record provides a model system for such investigation, representing an ecologically diverse group that dominated terrestrial ecosystems for 170 million years. Furthermore, with 10,000 species, extant dinosaurs (birds) are the most speciose living tetrapod clade. We assembled composite trees of 614-622 Mesozoic dinosaurs/birds, and a comprehensive body mass dataset using the scaling relationship of limb bone robustness. Maximum-likelihood modelling and the node height test reveal rapid evolutionary rates and a predominance of rapid shifts among size classes in early (Triassic) dinosaurs. This indicates an early burst niche-filling pattern and contrasts with previous studies that favoured gradualistic rates. Subsequently, rates declined in most lineages, which rarely exploited new ecological niches. However, feathered maniraptoran dinosaurs (including Mesozoic birds) sustained rapid evolution from at least the Middle Jurassic, suggesting that these taxa evaded the effects of niche saturation. This indicates that a long evolutionary history of continuing ecological innovation paved the way for a second great radiation of dinosaurs, in birds. We therefore demonstrate links between the predominantly extinct deep time adaptive radiation of non-avian dinosaurs and the phenomenal diversification of birds, via continuing rapid rates of evolution along the phylogenetic stem lineage. This raises the possibility that the uneven distribution of biodiversity results not just from large-scale extrapolation of the process of adaptive radiation in a few extant clades, but also from the maintenance of evolvability on vast time scales across the history of life, in key lineages.

@article{doi101371journalpbio1001853,
    author = "Benson, Roger and Campione, Nicolás E. and Carrano, Matthew T. and Mannion, Philip D. and Sullivan, Corwin and Upchurch, Paul and Evans, David C.",
    title = "Rates of Dinosaur Body Mass Evolution Indicate 170 Million Years of Sustained Ecological Innovation on the Avian Stem Lineage",
    year = "2014",
    journal = "PLoS Biology",
    abstract = "Large-scale adaptive radiations might explain the runaway success of a minority of extant vertebrate clades. This hypothesis predicts, among other things, rapid rates of morphological evolution during the early history of major groups, as lineages invade disparate ecological niches. However, few studies of adaptive radiation have included deep time data, so the links between extant diversity and major extinct radiations are unclear. The intensively studied Mesozoic dinosaur record provides a model system for such investigation, representing an ecologically diverse group that dominated terrestrial ecosystems for 170 million years. Furthermore, with 10,000 species, extant dinosaurs (birds) are the most speciose living tetrapod clade. We assembled composite trees of 614-622 Mesozoic dinosaurs/birds, and a comprehensive body mass dataset using the scaling relationship of limb bone robustness. Maximum-likelihood modelling and the node height test reveal rapid evolutionary rates and a predominance of rapid shifts among size classes in early (Triassic) dinosaurs. This indicates an early burst niche-filling pattern and contrasts with previous studies that favoured gradualistic rates. Subsequently, rates declined in most lineages, which rarely exploited new ecological niches. However, feathered maniraptoran dinosaurs (including Mesozoic birds) sustained rapid evolution from at least the Middle Jurassic, suggesting that these taxa evaded the effects of niche saturation. This indicates that a long evolutionary history of continuing ecological innovation paved the way for a second great radiation of dinosaurs, in birds. We therefore demonstrate links between the predominantly extinct deep time adaptive radiation of non-avian dinosaurs and the phenomenal diversification of birds, via continuing rapid rates of evolution along the phylogenetic stem lineage. This raises the possibility that the uneven distribution of biodiversity results not just from large-scale extrapolation of the process of adaptive radiation in a few extant clades, but also from the maintenance of evolvability on vast time scales across the history of life, in key lineages.",
    url = "https://doi.org/10.1371/journal.pbio.1001853",
    doi = "10.1371/journal.pbio.1001853",
    openalex = "W2155522161",
    references = "doi101007b97636, doi101017s009483730001263x, doi101017s009483730001280x, doi10103835086500, doi10103844766, doi101038nature11631, doi10108010635150490445706, doi101086284325, doi101093bioinformaticsbtm538, doi101093oso97801985052350010001, doi101093oso97801985404720010001, doi101098rspb20122526, doi101111j001438202003tb00285x, doi101111j1469185x201000137x, doi101111j15585646201201723x, doi101126science1144066, doi101126science1161833, doi101146annurevecolsys39110707173447, doi101159000452856, doi101186174170071060, doi101198tech2003s146, doi101371journalpbio1001853, doi101371journalpone0007390, doi101371journalpone0044318, doi10166612041, martinsander2006bone, openalexw2145250129"
}

We developed a three-dimensional, biomechanical computer model of the 36 major pelvic limb muscle groups in an ostrich (Struthio camelus) to investigate muscle function in this, the largest of extant birds and model organism for many studies of locomotor mechanics, body size, anatomy and evolution. Combined with experimental data, we use this model to test two main hypotheses. We first query whether ostriches use limb orientations (joint angles) that optimize the moment-generating capacities of their muscles during walking or running. Next, we test whether ostriches use limb orientations at mid-stance that keep their extensor muscles near maximal, and flexor muscles near minimal, moment arms. Our two hypotheses relate to the control priorities that a large bipedal animal might evolve under biomechanical constraints to achieve more effective static weight support. We find that ostriches do not use limb orientations to optimize the moment-generating capacities or moment arms of their muscles. We infer that dynamic properties of muscles or tendons might be better candidates for locomotor optimization. Regardless, general principles explaining why species choose particular joint orientations during locomotion are lacking, raising the question of whether such general principles exist or if clades evolve different patterns (e.g., weighting of muscle force-length or force-velocity properties in selecting postures). This leaves theoretical studies of muscle moment arms estimated for extinct animals at an impasse until studies of extant taxa answer these questions. Finally, we compare our model's results against those of two prior studies of ostrich limb muscle moment arms, finding general agreement for many muscles. Some flexor and extensor muscles exhibit self-stabilization patterns (posture-dependent switches between flexor/extensor action) that ostriches may use to coordinate their locomotion. However, some conspicuous areas of disagreement in our results illustrate some cautionary principles. Importantly, tendon-travel empirical measurements of muscle moment arms must be carefully designed to preserve 3D muscle geometry lest their accuracy suffer relative to that of anatomically realistic models. The dearth of accurate experimental measurements of 3D moment arms of muscles in birds leaves uncertainty regarding the relative accuracy of different modelling or experimental datasets such as in ostriches. Our model, however, provides a comprehensive set of 3D estimates of muscle actions in ostriches for the first time, emphasizing that avian limb mechanics are highly three-dimensional and complex, and how no muscles act purely in the sagittal plane. A comparative synthesis of experiments and models such as ours could provide powerful synthesis into how anatomy, mechanics and control interact during locomotion and how these interactions evolve. Such a framework could remove obstacles impeding the analysis of muscle function in extinct taxa.

@article{doi107717peerj1001,
    author = "Hutchinson, John R. and Rankin, Jeffery W. and Rubenson, Jonas and Rosenbluth, Kate H. and Siston, Robert A. and Delp, Scott L.",
    title = "Musculoskeletal modelling of an ostrich (Struthio camelus) pelvic limb: influence of limb orientation on muscular capacity during locomotion",
    year = "2015",
    journal = "PeerJ",
    abstract = "We developed a three-dimensional, biomechanical computer model of the 36 major pelvic limb muscle groups in an ostrich (Struthio camelus) to investigate muscle function in this, the largest of extant birds and model organism for many studies of locomotor mechanics, body size, anatomy and evolution. Combined with experimental data, we use this model to test two main hypotheses. We first query whether ostriches use limb orientations (joint angles) that optimize the moment-generating capacities of their muscles during walking or running. Next, we test whether ostriches use limb orientations at mid-stance that keep their extensor muscles near maximal, and flexor muscles near minimal, moment arms. Our two hypotheses relate to the control priorities that a large bipedal animal might evolve under biomechanical constraints to achieve more effective static weight support. We find that ostriches do not use limb orientations to optimize the moment-generating capacities or moment arms of their muscles. We infer that dynamic properties of muscles or tendons might be better candidates for locomotor optimization. Regardless, general principles explaining why species choose particular joint orientations during locomotion are lacking, raising the question of whether such general principles exist or if clades evolve different patterns (e.g., weighting of muscle force-length or force-velocity properties in selecting postures). This leaves theoretical studies of muscle moment arms estimated for extinct animals at an impasse until studies of extant taxa answer these questions. Finally, we compare our model's results against those of two prior studies of ostrich limb muscle moment arms, finding general agreement for many muscles. Some flexor and extensor muscles exhibit self-stabilization patterns (posture-dependent switches between flexor/extensor action) that ostriches may use to coordinate their locomotion. However, some conspicuous areas of disagreement in our results illustrate some cautionary principles. Importantly, tendon-travel empirical measurements of muscle moment arms must be carefully designed to preserve 3D muscle geometry lest their accuracy suffer relative to that of anatomically realistic models. The dearth of accurate experimental measurements of 3D moment arms of muscles in birds leaves uncertainty regarding the relative accuracy of different modelling or experimental datasets such as in ostriches. Our model, however, provides a comprehensive set of 3D estimates of muscle actions in ostriches for the first time, emphasizing that avian limb mechanics are highly three-dimensional and complex, and how no muscles act purely in the sagittal plane. A comparative synthesis of experiments and models such as ours could provide powerful synthesis into how anatomy, mechanics and control interact during locomotion and how these interactions evolve. Such a framework could remove obstacles impeding the analysis of muscle function in extinct taxa.",
    url = "https://doi.org/10.7717/peerj.1001",
    doi = "10.7717/peerj.1001",
    openalex = "W1544038153",
    references = "doi101002ajpa10408, doi101007s0001501000242, doi101111brv12071, doi101666100041, doi104202app20090075"
}

@article{doi101016jcub201609040,
    author = "Cabreira, Sérgio Furtado and Kellner, Alexander W. A. and Dias‐da‐Silva, Sérgio and da Silva, Lúcio Roberto and Bronzati, Mario and Marsola, Júlio C. A. and Müller, Rodrigo Temp and Bittencourt, Jonathas S. and Batista, Brunna Jul’Armando Rezende and Raugust, Tiago and Carrilho, Rodrigo and Brodt, André and Langer, Max C.",
    title = "A Unique Late Triassic Dinosauromorph Assemblage Reveals Dinosaur Ancestral Anatomy and Diet",
    year = "2016",
    journal = "Current Biology",
    url = "https://doi.org/10.1016/j.cub.2016.09.040",
    doi = "10.1016/j.cub.2016.09.040",
    openalex = "W2549642838",
    references = "crossref1998encyclopedia, doi101016jcub201311063, doi101016jearscirev201004001, doi101017s1477201906001970, doi101073pnas1011924108, doi10108002724634199110011426, doi101080027246342013818546, doi101080027246342013820113, doi101080147720192010484650, doi101126science1143325, doi101144sp3799, doi1012063521, doi1016710390290218, doi101671a1097, doi105281zenodo16171435, doi107717peerj1778"
}

Titanosauria is an exceptionally diverse, globally-distributed clade of sauropod dinosaurs that includes the largest known land animals. Knowledge of titanosaurian pedal structure is critical to understanding the stance and locomotion of these enormous herbivores and, by extension, gigantic terrestrial vertebrates as a whole. However, completely preserved pedes are extremely rare among Titanosauria, especially as regards the truly giant members of the group. Here we describe Notocolossus gonzalezparejasi gen. et sp. nov. from the Upper Cretaceous of Mendoza Province, Argentina. With a powerfully-constructed humerus 1.76 m in length, Notocolossus is one of the largest known dinosaurs. Furthermore, the complete pes of the new taxon exhibits a strikingly compact, homogeneous metatarsus--seemingly adapted for bearing extraordinary weight--and truncated unguals, morphologies that are otherwise unknown in Sauropoda. The pes underwent a near-progressive reduction in the number of phalanges along the line to derived titanosaurs, eventually resulting in the reduced hind foot of these sauropods.

@article{doi101038srep19165,
    author = "Riga, Bernardo J. González and Lamanna, Matthew C. and David, Leonardo D. Ortiz and Calvo, Jorge O. and Coria, Juan Pedro",
    title = "A gigantic new dinosaur from Argentina and the evolution of the sauropod hind foot",
    year = "2016",
    journal = "Scientific Reports",
    abstract = "Titanosauria is an exceptionally diverse, globally-distributed clade of sauropod dinosaurs that includes the largest known land animals. Knowledge of titanosaurian pedal structure is critical to understanding the stance and locomotion of these enormous herbivores and, by extension, gigantic terrestrial vertebrates as a whole. However, completely preserved pedes are extremely rare among Titanosauria, especially as regards the truly giant members of the group. Here we describe Notocolossus gonzalezparejasi gen. et sp. nov. from the Upper Cretaceous of Mendoza Province, Argentina. With a powerfully-constructed humerus 1.76 m in length, Notocolossus is one of the largest known dinosaurs. Furthermore, the complete pes of the new taxon exhibits a strikingly compact, homogeneous metatarsus--seemingly adapted for bearing extraordinary weight--and truncated unguals, morphologies that are otherwise unknown in Sauropoda. The pes underwent a near-progressive reduction in the number of phalanges along the line to derived titanosaurs, eventually resulting in the reduced hind foot of these sauropods.",
    url = "https://doi.org/10.1038/srep19165",
    doi = "10.1038/srep19165",
    openalex = "W2419063019",
    references = "doi101038srep06196, doi101046j10963642200200029x, doi101111j10960031200800217x, doi101111j109636421998tb00569x, doi101111zoj12029, doi101186174170071060, doi101371journalpbio1001853, doi101371journalpone0017114, doi101525california97805202420980030015, doi1022179revmacn7344, doi105710amegh261210131889, doi105962p234849, openalexw581267017"
}

Theropod dinosaurs from the Late Jurassic of Gondwana are still poorly known, with Elaphrosaurus bambergiJanensch, 1920, from the late Kimmeridgian of Tendaguru, Tanzania, being the only taxon represented by more than isolated remains from Africa. Having long been considered a coelurosaurian, more specifically an ornithomimosaur, Elaphrosaurus is currently regarded as a basal ceratosaur. Here, we revise the osteology and phylogenetic position of this important taxon. Elaphrosaurus shows many unusual osteological characters, including extremely elongated and constricted cervical vertebrae, an expansive shoulder girdle with strongly modified forelimbs, a relatively small ilium, and elongate hindlimbs with a very small ascending process of the astragalus that is fused to the tibia. We found this taxon to share many derived characters with noasaurids, such as: strongly elongate cervical and dorsal vertebrae; low, rectangular neural spines in the mid-caudal vertebrae; presence of only an anterior centrodiapophyseal lamina in anterior caudal vertebrae; presence of a wide, U–shaped notch between the glenoid and the anteroventral hook in the coracoid; a laterally flared postacetabular blade of the ilium; a flat anterior side of the distal tibia; and a reduced shaft of metatarsal II. Our analysis placed Elaphrosaurus within a dichotomous Noasauridae as part of a Jurassic subclade, here termed Elaphrosaurinae, that otherwise includes taxa from eastern Asia. These results underscore the long and complex evolutionary history of abelisauroids, which is still only beginning to be understood.

@article{doi101111zoj12425,
    author = "Rauhut, Oliver W. M. and Carrano, Matthew T.",
    title = "The theropod dinosaur Elaphrosaurus bambergi Janensch, 1920, from the Late Jurassic of Tendaguru, Tanzania",
    year = "2016",
    journal = "Zoological Journal of the Linnean Society",
    abstract = "Theropod dinosaurs from the Late Jurassic of Gondwana are still poorly known, with Elaphrosaurus bambergiJanensch, 1920, from the late Kimmeridgian of Tendaguru, Tanzania, being the only taxon represented by more than isolated remains from Africa. Having long been considered a coelurosaurian, more specifically an ornithomimosaur, Elaphrosaurus is currently regarded as a basal ceratosaur. Here, we revise the osteology and phylogenetic position of this important taxon. Elaphrosaurus shows many unusual osteological characters, including extremely elongated and constricted cervical vertebrae, an expansive shoulder girdle with strongly modified forelimbs, a relatively small ilium, and elongate hindlimbs with a very small ascending process of the astragalus that is fused to the tibia. We found this taxon to share many derived characters with noasaurids, such as: strongly elongate cervical and dorsal vertebrae; low, rectangular neural spines in the mid-caudal vertebrae; presence of only an anterior centrodiapophyseal lamina in anterior caudal vertebrae; presence of a wide, U–shaped notch between the glenoid and the anteroventral hook in the coracoid; a laterally flared postacetabular blade of the ilium; a flat anterior side of the distal tibia; and a reduced shaft of metatarsal II. Our analysis placed Elaphrosaurus within a dichotomous Noasauridae as part of a Jurassic subclade, here termed Elaphrosaurinae, that otherwise includes taxa from eastern Asia. These results underscore the long and complex evolutionary history of abelisauroids, which is still only beginning to be understood.",
    url = "https://doi.org/10.1111/zoj.12425",
    doi = "10.1111/zoj.12425",
    openalex = "W2340352440",
    references = "crossref1998encyclopedia, doi101002mmng200900004, doi101016jcretres201304001, doi101016jpgeola201205008, doi101017s0016756804000330, doi101017s0025315400028575, doi10108002724634199610011283, doi101098rspb20120660, doi101098rspl18870117, doi1011112041210x12226, doi101111j10960031200800217x, doi101126science28454232137, doi101371journalpone0062047, doi102475ajss319111253, doi105281zenodo16171435, doi105860choice353642, openalexw1565584485, openalexw3215057009, openalexw3217097258"
}

Titanosauria was the most diverse and successful lineage of sauropod dinosaurs. This clade had its major radiation during the middle Early Cretaceous and survived up to the end of that period. Among sauropods, this lineage has the most disparate values of body mass, including the smallest and largest sauropods known. Although recent findings have improved our knowledge on giant titanosaur anatomy, there are still many unknown aspects about their evolution, especially for the most gigantic forms and the evolution of body mass in this clade. Here we describe a new giant titanosaur, which represents the largest species described so far and one of the most complete titanosaurs. Its inclusion in an extended phylogenetic analysis and the optimization of body mass reveals the presence of an endemic clade of giant titanosaurs inhabited Patagonia between the Albian and the Santonian. This clade includes most of the giant species of titanosaurs and represents the major increase in body mass in the history of Titanosauria.

@article{doi101098rspb20171219,
    author = "Carballido, José Luis and Pol, Diego and Otero, Alejandro and Cerda, Ignacio A. and Salgado, Leonardo and Garrido, Alberto C. and Ramezani, Jahandar and Cúneo, N. Rubén and Krause, J. Marcelo",
    title = "A new giant titanosaur sheds light on body mass evolution among sauropod dinosaurs",
    year = "2017",
    journal = "Proceedings of the Royal Society B Biological Sciences",
    abstract = "Titanosauria was the most diverse and successful lineage of sauropod dinosaurs. This clade had its major radiation during the middle Early Cretaceous and survived up to the end of that period. Among sauropods, this lineage has the most disparate values of body mass, including the smallest and largest sauropods known. Although recent findings have improved our knowledge on giant titanosaur anatomy, there are still many unknown aspects about their evolution, especially for the most gigantic forms and the evolution of body mass in this clade. Here we describe a new giant titanosaur, which represents the largest species described so far and one of the most complete titanosaurs. Its inclusion in an extended phylogenetic analysis and the optimization of body mass reveals the presence of an endemic clade of giant titanosaurs inhabited Patagonia between the Albian and the Santonian. This clade includes most of the giant species of titanosaurs and represents the major increase in body mass in the history of Titanosauria.",
    url = "https://doi.org/10.1098/rspb.2017.1219",
    doi = "10.1098/rspb.2017.1219",
    openalex = "W2742460947",
    references = "doi101016jcretres201304001, doi101038srep06196, doi101038srep19165, doi101046j10963642200200029x, doi101098rsbl20120263, doi101098rspb20171219, doi101111j10960031200600122x, doi101111j10960031200800217x, doi101111j109636421998tb00569x, doi101111j1469185x201000137x, doi101111zoj12029, doi1011300091761320020300123dsproe20co2, doi101186174170071060, doi101371journalpbio1001853, doi101371journalpone0093105, doi101525california97805202420980030015, doi1016660094837320080340247ositlb20co2, doi1022179revmacn7344, doi10560219780801881206"
}

Abstract The largest known dinosaurs weighed at least 20 million times as much as the smallest, indicating exceptional phenotypic divergence. Previous studies have focused on extreme giant sizes, tests of Cope's rule, and miniaturization on the line leading to birds. We use non‐uniform macroevolutionary models based on Ornstein–Uhlenbeck and trend processes to unify these observations, asking: what patterns of evolutionary rates, directionality and constraint explain the diversification of dinosaur body mass? We find that dinosaur evolution is constrained by attraction to discrete body size optima that undergo rare, but abrupt, evolutionary shifts. This model explains both the rarity of multi‐lineage directional trends, and the occurrence of abrupt directional excursions during the origins of groups such as tiny pygostylian birds and giant sauropods. Most expansion of trait space results from rare, constraint‐breaking innovations in just a small number of lineages. These lineages shifted rapidly into novel regions of trait space, occasionally to small sizes, but most often to large or giant sizes. As with Cenozoic mammals, intermediate body sizes were typically attained only transiently by lineages on a trajectory from small to large size. This demonstrates that bimodality in the macroevolutionary adaptive landscape for land vertebrates has existed for more than 200 million years.

@article{doi101111pala12329,
    author = "Benson, Roger and Hunt, Gene and Carrano, Matthew T. and Campione, Nicolás E.",
    title = "Cope's rule and the adaptive landscape of dinosaur body size evolution",
    year = "2017",
    journal = "Palaeontology",
    abstract = "Abstract The largest known dinosaurs weighed at least 20 million times as much as the smallest, indicating exceptional phenotypic divergence. Previous studies have focused on extreme giant sizes, tests of Cope's rule, and miniaturization on the line leading to birds. We use non‐uniform macroevolutionary models based on Ornstein–Uhlenbeck and trend processes to unify these observations, asking: what patterns of evolutionary rates, directionality and constraint explain the diversification of dinosaur body mass? We find that dinosaur evolution is constrained by attraction to discrete body size optima that undergo rare, but abrupt, evolutionary shifts. This model explains both the rarity of multi‐lineage directional trends, and the occurrence of abrupt directional excursions during the origins of groups such as tiny pygostylian birds and giant sauropods. Most expansion of trait space results from rare, constraint‐breaking innovations in just a small number of lineages. These lineages shifted rapidly into novel regions of trait space, occasionally to small sizes, but most often to large or giant sizes. As with Cenozoic mammals, intermediate body sizes were typically attained only transiently by lineages on a trajectory from small to large size. This demonstrates that bimodality in the macroevolutionary adaptive landscape for land vertebrates has existed for more than 200 million years.",
    url = "https://doi.org/10.1111/pala.12329",
    doi = "10.1111/pala.12329",
    openalex = "W2766635059",
    references = "doi101007b97636, doi101007s0026501010296, doi101016jpalaeo201206027, doi101017pab201615, doi101038229172a0, doi10103844766, doi101038nature04633, doi101038ncomms7987, doi101038srep06196, doi101073pnas0708903105, doi101073pnas1302642110, doi10108010635150490445706, doi101086284325, doi101093bioinformaticsbtg412, doi101098rspb20122526, doi101098rspb20171219, doi101109tac19741100705, doi1011112041210x12226, doi101111j1469185x201000137x, doi101111j1469185x201100190x, doi101111j2041210x201100169x, doi101111j2041210x201200223x, doi101126scienceaag1772, doi101146annurevearth060313054858, doi101186174170071060, doi101198tech2003s146, doi101371journalpbio1001853, doi101371journalpone0007390, doi101371journalpone0033539, doi101371journalpone0044318, doi101371journalpone0051925, doi1022179revmacn14372, erickson2014on, martinsander2006bone, openalexw1550095290, openalexw2473973115, openalexw3086315876"
}

The energetic costs of terrestrial locomotion are placed in the context of the fuel sources that animals use for generating adenosine triphosphate (ATP) and how these fuel sources affect an animal’s capacity for sustainable aerobic metabolism. Aerobic capacity and energy use are closely linked to an animal’s thermoregulatory strategy. Patterns of energy use across terrestrial gaits, sloped substrates and level ground are examined alongside explanatory models. The energetics of terrestrial locomotion is compared with the energetics of swimming and flight. Whereas the support of an animal’s weight against gravity dominates the cost of moving on land and through air, overcoming resistive forces of drag strongly affects the energy cost of movement through water and air. The physical properties of land, water and air influence how energy use changes with the speed of movement. Given these energetic considerations, animals use different locomotor strategies and mechanisms to avoid fatigue and increase endurance capacity.

@book{crossref2018energetics,
    title = "Energetics of Locomotion",
    year = "2018",
    booktitle = "Oxford Scholarship Online",
    abstract = "The energetic costs of terrestrial locomotion are placed in the context of the fuel sources that animals use for generating adenosine triphosphate (ATP) and how these fuel sources affect an animal’s capacity for sustainable aerobic metabolism. Aerobic capacity and energy use are closely linked to an animal’s thermoregulatory strategy. Patterns of energy use across terrestrial gaits, sloped substrates and level ground are examined alongside explanatory models. The energetics of terrestrial locomotion is compared with the energetics of swimming and flight. Whereas the support of an animal’s weight against gravity dominates the cost of moving on land and through air, overcoming resistive forces of drag strongly affects the energy cost of movement through water and air. The physical properties of land, water and air influence how energy use changes with the speed of movement. Given these energetic considerations, animals use different locomotor strategies and mechanisms to avoid fatigue and increase endurance capacity.",
    url = "https://doi.org/10.1093/oso/9780198743156.003.0003",
    doi = "10.1093/oso/9780198743156.003.0003",
    openalex = "W4256518784"
}

@article{doi101016jcub201807057,
    author = "Xu, Xing and Choiniere, Jonah N. and Tan, Qingwei and Benson, Roger and Clark, James M. and Sullivan, Corwin and Zhao, Qi and Han, Fenglu and Ma, Qingyu and He, Yiming and Wang, Shuo and Hai, Xing and Tan, Lin",
    title = "Two Early Cretaceous Fossils Document Transitional Stages in Alvarezsaurian Dinosaur Evolution",
    year = "2018",
    journal = "Current Biology",
    url = "https://doi.org/10.1016/j.cub.2018.07.057",
    doi = "10.1016/j.cub.2018.07.057",
    openalex = "W2888370827",
    references = "doi101080147720192010488045, doi101080147720192013781067, doi101111pala12329, doi1012066391"
}

The Jurassic Yanliao theropods have offered rare glimpses of the early paravian evolution and particularly of bird origins, but, with the exception of the bizarre scansoriopterygids, they have shown similar skeletal and integumentary morphologies. Here we report a distinctive new Yanliao theropod species bearing prominent lacrimal crests, bony ornaments previously known from more basal theropods. It shows longer arm and leg feathers than Anchiornis and tail feathers with asymmetrical vanes forming a tail surface area even larger than that in Archaeopteryx. Nanostructures, interpreted as melanosomes, are morphologically similar to organized, platelet-shaped organelles that produce bright iridescent colours in extant birds. The new species indicates the presence of bony ornaments, feather colour and flight-related features consistent with proposed rapid character evolution and significant diversity in signalling and locomotor strategies near bird origins.

@article{doi101038s4146701702515y,
    author = "Hu, Dongyu and Clarke, Julia A. and Eliason, Chad M. and Qiu, Rui and Li, Quanguo and Shawkey, Matthew D. and Zhao, Cuilin and D’Alba, Liliana and Jiang, Jinkai and Xu, Xing",
    title = "A bony-crested Jurassic dinosaur with evidence of iridescent plumage highlights complexity in early paravian evolution",
    year = "2018",
    journal = "Nature Communications",
    abstract = "The Jurassic Yanliao theropods have offered rare glimpses of the early paravian evolution and particularly of bird origins, but, with the exception of the bizarre scansoriopterygids, they have shown similar skeletal and integumentary morphologies. Here we report a distinctive new Yanliao theropod species bearing prominent lacrimal crests, bony ornaments previously known from more basal theropods. It shows longer arm and leg feathers than Anchiornis and tail feathers with asymmetrical vanes forming a tail surface area even larger than that in Archaeopteryx. Nanostructures, interpreted as melanosomes, are morphologically similar to organized, platelet-shaped organelles that produce bright iridescent colours in extant birds. The new species indicates the presence of bony ornaments, feather colour and flight-related features consistent with proposed rapid character evolution and significant diversity in signalling and locomotor strategies near bird origins.",
    url = "https://doi.org/10.1038/s41467-017-02515-y",
    doi = "10.1038/s41467-017-02515-y",
    openalex = "W2783693197",
    references = "doi101038nature13467, doi101038nature14423, doi101038ncomms12931, doi101038ncomms14972, doi1011112041210x12226"
}

The Late Jurassic Tendaguru Formation of Tanzania, southeastern Africa, records a diverse and abundant sauropod fauna, including the flagellicaudatan diplodocoids Dicraeosaurus and Tornieria, and the brachiosaurid titanosauriform Giraffatitan. However, the taxonomic affinities of other sympatric sauropod taxa and remains are poorly understood. Here, we critically reassess and redescribe these problematic taxa, and present the largest phylogenetic analysis for sauropods (117 taxa scored for 542 characters) to explore their placement within Eusauropoda. A full re-description of the holotype of Janenschia, and all referable remains, supports its validity and placement as a nonneosauropod eusauropod. New information on the internal pneumatic tissue structure of the anterior dorsal vertebrae of the enigmatic Tendaguria tanzaniensis, coupled with a full re-description, results in its novel placement as a turiasaur. A previously referred caudal sequence cannot be assigned to Janenschia and displays several features that indicate a close relationship with Middle–Late Jurassic East Asian mamenchisaurids. It can be diagnosed by six autapomorphies, and we erect the new taxon Wamweracaudia keranjei n. gen. n. sp. The Tendaguru Formation shares representatives of nearly all sauropod lineages with Middle Jurassic–earliest Cretaceous global faunas, but displays a greater range of diversity than any of those faunas considered individually.

@article{doi101093zoolinneanzly068,
    author = "Mannion, Philip D. and Upchurch, Paul and Schwarz, Daniela and Wings, Oliver",
    title = "Taxonomic affinities of the putative titanosaurs from the Late Jurassic Tendaguru Formation of Tanzania: phylogenetic and biogeographic implications for eusauropod dinosaur evolution",
    year = "2018",
    journal = "Zoological Journal of the Linnean Society",
    abstract = "The Late Jurassic Tendaguru Formation of Tanzania, southeastern Africa, records a diverse and abundant sauropod fauna, including the flagellicaudatan diplodocoids Dicraeosaurus and Tornieria, and the brachiosaurid titanosauriform Giraffatitan. However, the taxonomic affinities of other sympatric sauropod taxa and remains are poorly understood. Here, we critically reassess and redescribe these problematic taxa, and present the largest phylogenetic analysis for sauropods (117 taxa scored for 542 characters) to explore their placement within Eusauropoda. A full re-description of the holotype of Janenschia, and all referable remains, supports its validity and placement as a nonneosauropod eusauropod. New information on the internal pneumatic tissue structure of the anterior dorsal vertebrae of the enigmatic Tendaguria tanzaniensis, coupled with a full re-description, results in its novel placement as a turiasaur. A previously referred caudal sequence cannot be assigned to Janenschia and displays several features that indicate a close relationship with Middle–Late Jurassic East Asian mamenchisaurids. It can be diagnosed by six autapomorphies, and we erect the new taxon Wamweracaudia keranjei n. gen. n. sp. The Tendaguru Formation shares representatives of nearly all sauropod lineages with Middle Jurassic–earliest Cretaceous global faunas, but displays a greater range of diversity than any of those faunas considered individually.",
    url = "https://doi.org/10.1093/zoolinnean/zly068",
    doi = "10.1093/zoolinnean/zly068",
    openalex = "W2911482806",
    references = "doi101002mmng19994860020102, doi101002mmng19994860020109, doi101002mmng200900004, doi101016jcretres201603008, doi101016jearscirev201203002, doi101016jgr201403014, doi101017s0016756804000330, doi101038ncomms3929, doi101038s41467018051281, doi101038srep19165, doi101038srep34467, doi101080027246342011557116, doi101080027246342012671204, doi101080027246342013776562, doi101093sysbiosyu056, doi101093zoolinneanzlx103, doi101098rspb20120660, doi101098rspb20171219, doi101111cla12160, doi101111j10960031200800217x, doi101111j10963642201000620x, doi101111pala12142, doi101111zoj12029, doi101111zoj12425, doi101144001676492006032, doi101371journalpone0006924, doi101371journalpone0017114, doi101371journalpone0037122, doi101371journalpone0079420, doi101371journalpone0125819, doi1018814epiiugs2013v36i3002, doi1021425f55419694, doi1022179revmacn7344, doi1023073802723, doi1026879529, doi10274700206814489791, doi105281zenodo16171435, doi105710amegh261210131889, doi105860choice331556, doi107717peerj857, heinrich1998late, openalexw1545181283"
}

@article{doi101016jcub201910050,
    author = "Button, David J. and Zanno, Lindsay E.",
    title = "Repeated Evolution of Divergent Modes of Herbivory in Non-avian Dinosaurs",
    year = "2019",
    journal = "Current Biology",
    url = "https://doi.org/10.1016/j.cub.2019.10.050",
    doi = "10.1016/j.cub.2019.10.050",
    openalex = "W2993362957",
    references = "doi101002ar23306, doi101002ar23988, doi10100797836426953391, doi101007s0011401411439, doi101007s0042701605392, doi101016jcub201609040, doi101016jcub201610043, doi101016jpalaeo201803006, doi101038nature24679, doi101038ncomms3827, doi101038srep19165, doi101038srep44942, doi101073pnas1310711110, doi101073pnas1319091111, doi10108002724631003763516, doi101080147720192010488045, doi1010801477201920151059985, doi101086414425, doi101093bioinformatics176520, doi101093bioinformaticsbtg180, doi101093bioinformaticsbtm069, doi101098rsos161086, doi101098rspb20110410, doi101098rspb20122526, doi101098rspb20171219, doi101111j2041210x201100169x, doi101371journalpone0078573, doi101371journalpone0079420, doi101371journalpone0092022, doi101371journalpone0098605, doi101371journalpone0112055, doi1017161paleo180818764, doi102307jctvjsf433, doi105281zenodo13315375, doi105860choice396411, doi107717peerj1032, doi107717peerj1523, openalexw2282537990"
}

Titanosaurs were a globally distributed clade of Cretaceous sauropods. Historically regarded as a primarily Gondwanan radiation, there is a growing number of Eurasian taxa, with several putative titanosaurs contemporaneous with, or even pre-dating, the oldest known Southern Hemisphere remains. The early Late Cretaceous Jinhua Formation, in Zhejiang Province, China, has yielded two putative titanosaurs, Jiangshanosaurus lixianensis and Dongyangosaurus sinensis. Here, we provide a detailed re-description and diagnosis of Jiangshanosaurus, as well as new anatomical information on Dongyangosaurus. Previously, a 'derived' titanosaurian placement for Jiangshanosaurus was primarily based on the presence of procoelous anterior caudal centra. We show that this taxon had amphicoelous anterior-middle caudal centra. Its only titanosaurian synapomorphy is that the dorsal margins of the scapula and coracoid are approximately level with one another. Dongyangosaurus can clearly be differentiated from Jiangshanosaurus, and displays features that indicate a closer relationship to the titanosaur radiation. Revised scores for both taxa are incorporated into an expanded phylogenetic data matrix, comprising 124 taxa scored for 548 characters. Under equal weights parsimony, Jiangshanosaurus is recovered as a member of the non-titanosaurian East Asian somphospondylan clade Euhelopodidae, and Dongyangosaurus lies just outside of Titanosauria. However, when extended implied weighting is applied, both taxa are placed within Titanosauria. Most other 'middle' Cretaceous East Asian sauropods are probably non-titanosaurian somphospondylans, but at least Xianshanosaurus appears to belong to the titanosaur radiation. Our analyses also recover the Early Cretaceous European sauropod Normanniasaurus genceyi as a 'derived' titanosaur, clustering with Gondwanan taxa. These results provide further support for a widespread diversification of titanosaurs by at least the Early Cretaceous.

@article{doi101098rsos191057,
    author = "Mannion, Philip D. and Upchurch, Paul and Jin, Xingsheng and Zheng, Wenjie",
    title = "New information on the Cretaceous sauropod dinosaurs of Zhejiang Province, China: impact on Laurasian titanosauriform phylogeny and biogeography",
    year = "2019",
    journal = "Royal Society Open Science",
    abstract = "Titanosaurs were a globally distributed clade of Cretaceous sauropods. Historically regarded as a primarily Gondwanan radiation, there is a growing number of Eurasian taxa, with several putative titanosaurs contemporaneous with, or even pre-dating, the oldest known Southern Hemisphere remains. The early Late Cretaceous Jinhua Formation, in Zhejiang Province, China, has yielded two putative titanosaurs, Jiangshanosaurus lixianensis and Dongyangosaurus sinensis. Here, we provide a detailed re-description and diagnosis of Jiangshanosaurus, as well as new anatomical information on Dongyangosaurus. Previously, a 'derived' titanosaurian placement for Jiangshanosaurus was primarily based on the presence of procoelous anterior caudal centra. We show that this taxon had amphicoelous anterior-middle caudal centra. Its only titanosaurian synapomorphy is that the dorsal margins of the scapula and coracoid are approximately level with one another. Dongyangosaurus can clearly be differentiated from Jiangshanosaurus, and displays features that indicate a closer relationship to the titanosaur radiation. Revised scores for both taxa are incorporated into an expanded phylogenetic data matrix, comprising 124 taxa scored for 548 characters. Under equal weights parsimony, Jiangshanosaurus is recovered as a member of the non-titanosaurian East Asian somphospondylan clade Euhelopodidae, and Dongyangosaurus lies just outside of Titanosauria. However, when extended implied weighting is applied, both taxa are placed within Titanosauria. Most other 'middle' Cretaceous East Asian sauropods are probably non-titanosaurian somphospondylans, but at least Xianshanosaurus appears to belong to the titanosaur radiation. Our analyses also recover the Early Cretaceous European sauropod Normanniasaurus genceyi as a 'derived' titanosaur, clustering with Gondwanan taxa. These results provide further support for a widespread diversification of titanosaurs by at least the Early Cretaceous.",
    url = "https://doi.org/10.1098/rsos.191057",
    doi = "10.1098/rsos.191057",
    openalex = "W2970495169",
    references = "doi101016jcretres201603008, doi101016jgr201403014, doi101016jjsames201411008, doi101016jpalaeo201206008, doi101038srep34467, doi101080027246342012671204, doi101093zoolinneanzlx103, doi101093zoolinneanzly068, doi101098rspb20171219, doi101111brv12255, doi1011646zootaxa384811, doi101371journalpone0125819, doi103897zookeys4698439"
}

Inferring the body mass of fossil taxa, such as non-avian dinosaurs, provides a powerful tool for interpreting physiological and ecological properties, as well as the ability to study these traits through deep time and within a macroevolutionary context. As a result, over the past 100 years a number of studies advanced methods for estimating mass in dinosaurs and other extinct taxa. These methods can be categorized into two major approaches: volumetric-density (VD) and extant-scaling (ES). The former receives the most attention in non-avian dinosaurs and advanced appreciably over the last century: from initial physical scale models to three-dimensional (3D) virtual techniques that utilize scanned data obtained from entire skeletons. The ES approach is most commonly applied to extinct members of crown clades but some equations are proposed and utilized in non-avian dinosaurs. Because both approaches share a common goal, they are often viewed in opposition to one another. However, current palaeobiological research problems are often approach specific and, therefore, the decision to utilize a VD or ES approach is largely question dependent. In general, biomechanical and physiological studies benefit from the full-body reconstruction provided through a VD approach, whereas large-scale evolutionary and ecological studies require the extensive data sets afforded by an ES approach. This study summarizes both approaches to body mass estimation in stem-group taxa, specifically non-avian dinosaurs, and provides a comparative quantitative framework to reciprocally illuminate and corroborate VD and ES approaches. The results indicate that mass estimates are largely consistent between approaches: 73% of VD reconstructions occur within the expected 95% prediction intervals of the ES relationship. However, almost three quarters of outliers occur below the lower 95% prediction interval, indicating that VD mass estimates are, on average, lower than would be expected given their stylopodial circumferences. Inconsistencies (high residual and per cent prediction deviation values) are recovered to a varying degree among all major dinosaurian clades along with an overall tendency for larger deviations between approaches among small-bodied taxa. Nonetheless, our results indicate a strong corroboration between recent iterations of the VD approach based on 3D specimen scans suggesting that our current understanding of size in dinosaurs, and hence its biological correlates, has improved over time. We advance that VD and ES approaches have fundamentally (metrically) different advantages and, hence, the comparative framework used and advocated here combines the accuracy afforded by ES with the precision provided by VD and permits the rapid identification of discrepancies with the potential to open new areas of discussion.

@article{doi101111brv12638,
    author = "Campione, Nicolás E. and Evans, David C.",
    title = "The accuracy and precision of body mass estimation in non‐avian dinosaurs",
    year = "2020",
    journal = "Biological reviews/Biological reviews of the Cambridge Philosophical Society",
    abstract = "Inferring the body mass of fossil taxa, such as non-avian dinosaurs, provides a powerful tool for interpreting physiological and ecological properties, as well as the ability to study these traits through deep time and within a macroevolutionary context. As a result, over the past 100 years a number of studies advanced methods for estimating mass in dinosaurs and other extinct taxa. These methods can be categorized into two major approaches: volumetric-density (VD) and extant-scaling (ES). The former receives the most attention in non-avian dinosaurs and advanced appreciably over the last century: from initial physical scale models to three-dimensional (3D) virtual techniques that utilize scanned data obtained from entire skeletons. The ES approach is most commonly applied to extinct members of crown clades but some equations are proposed and utilized in non-avian dinosaurs. Because both approaches share a common goal, they are often viewed in opposition to one another. However, current palaeobiological research problems are often approach specific and, therefore, the decision to utilize a VD or ES approach is largely question dependent. In general, biomechanical and physiological studies benefit from the full-body reconstruction provided through a VD approach, whereas large-scale evolutionary and ecological studies require the extensive data sets afforded by an ES approach. This study summarizes both approaches to body mass estimation in stem-group taxa, specifically non-avian dinosaurs, and provides a comparative quantitative framework to reciprocally illuminate and corroborate VD and ES approaches. The results indicate that mass estimates are largely consistent between approaches: 73\% of VD reconstructions occur within the expected 95\% prediction intervals of the ES relationship. However, almost three quarters of outliers occur below the lower 95\% prediction interval, indicating that VD mass estimates are, on average, lower than would be expected given their stylopodial circumferences. Inconsistencies (high residual and per cent prediction deviation values) are recovered to a varying degree among all major dinosaurian clades along with an overall tendency for larger deviations between approaches among small-bodied taxa. Nonetheless, our results indicate a strong corroboration between recent iterations of the VD approach based on 3D specimen scans suggesting that our current understanding of size in dinosaurs, and hence its biological correlates, has improved over time. We advance that VD and ES approaches have fundamentally (metrically) different advantages and, hence, the comparative framework used and advocated here combines the accuracy afforded by ES with the precision provided by VD and permits the rapid identification of discrepancies with the potential to open new areas of discussion.",
    url = "https://doi.org/10.1111/brv.12638",
    doi = "10.1111/brv.12638",
    openalex = "W3082346069",
    references = "doi101016jcub201706071, doi101016jpalaeo201206027, doi101017cbo9780511608551, doi101038417070a, doi101038srep06196, doi101086303327, doi101098rsbl20120263, doi101098rspb20060443, doi101098rspb20171219, doi1011112041210x12226, doi101111evo12150, doi101111j17447429200700272x, doi101111j2041210x201100153x, doi101111pala12329, doi101126science1061967, doi101152physrev1947274511, doi101371journalpone0044318, doi101371journalpone0051925, doi101371journalpone0081917, doi101371journalpone0082000, doi107717peerj857, openalexw1558456135, openalexw195142154, openalexw2593733766, openalexw260994251, pontzer2009biomechanics"
}

A milestone in vertebrate evolution, the transition from water to land, owes its success to the development of a sprawling body plan that enabled an amphibious lifestyle. The body, originally adapted for swimming, evolved to benefit from limbs that enhanced its locomotion capabilities on submerged and dry ground. The first terrestrial animals used sprawling locomotion, a type of legged locomotion in which limbs extend laterally from the body (as opposed to erect locomotion, in which limbs extend vertically below the body). This type of locomotion—exhibited, for instance, by salamanders, lizards, and crocodiles—has been studied in a variety of fields, including neuroscience, biomechanics, evolution, and paleontology. Robotics can benefit from these studies to design amphibious robots capable of swimming and walking, with interesting applications in field robotics, in particular for search and rescue, inspection, and environmental monitoring. In return, robotics can provide useful scientific tools to test hypotheses in neuroscience, biomechanics, and paleontology. For instance, robots have been used to test hypotheses about the organization of neural circuits that can switch between swimming and walking under the control of simple modulation signals, as well as to identify the most likely gaits of extinct sprawling animals. Here, I review different aspects of amphibious and sprawling locomotion, namely gait characteristics, neurobiology, numerical models, and sprawling robots, and discuss fruitful interactions between robotics and other scientific fields.

@article{doi101146annurevcontrol091919095731,
    author = "Ijspeert, Auke Jan",
    title = "Amphibious and Sprawling Locomotion: From Biology to Robotics and Back",
    year = "2020",
    journal = "Annual Review of Control Robotics and Autonomous Systems",
    abstract = "A milestone in vertebrate evolution, the transition from water to land, owes its success to the development of a sprawling body plan that enabled an amphibious lifestyle. The body, originally adapted for swimming, evolved to benefit from limbs that enhanced its locomotion capabilities on submerged and dry ground. The first terrestrial animals used sprawling locomotion, a type of legged locomotion in which limbs extend laterally from the body (as opposed to erect locomotion, in which limbs extend vertically below the body). This type of locomotion—exhibited, for instance, by salamanders, lizards, and crocodiles—has been studied in a variety of fields, including neuroscience, biomechanics, evolution, and paleontology. Robotics can benefit from these studies to design amphibious robots capable of swimming and walking, with interesting applications in field robotics, in particular for search and rescue, inspection, and environmental monitoring. In return, robotics can provide useful scientific tools to test hypotheses in neuroscience, biomechanics, and paleontology. For instance, robots have been used to test hypotheses about the organization of neural circuits that can switch between swimming and walking under the control of simple modulation signals, as well as to identify the most likely gaits of extinct sprawling animals. Here, I review different aspects of amphibious and sprawling locomotion, namely gait characteristics, neurobiology, numerical models, and sprawling robots, and discuss fruitful interactions between robotics and other scientific fields.",
    url = "https://doi.org/10.1146/annurev-control-091919-095731",
    doi = "10.1146/annurev-control-091919-095731",
    openalex = "W2998026442",
    references = "doi101086physzool67130163845, doi101098rsif20151089, doi103390biomimetics4030060"
}

Ornithischians form a large clade of globally distributed Mesozoic dinosaurs, and represent one of their three major radiations. Throughout their evolutionary history, exceeding 134 million years, ornithischians evolved considerable morphological disparity, expressed especially through the cranial and osteodermal features of their most distinguishable representatives. The nearly two-century-long research history on ornithischians has resulted in the recognition of numerous diverse lineages, many of which have been named. Following the formative publications establishing the theoretical foundation of phylogenetic nomenclature throughout the 1980s and 1990s, many of the proposed names of ornithischian clades were provided with phylogenetic definitions. Some of these definitions have proven useful and have not been changed, beyond the way they were formulated, since their introduction. Some names, however, have multiple definitions, making their application ambiguous. Recent implementation of the International Code of Phylogenetic Nomenclature (ICPN, or PhyloCode) offers the opportunity to explore the utility of previously proposed definitions of established taxon names. Since the Articles of the ICPN are not to be applied retroactively, all phylogenetic definitions published prior to its implementation remain informal (and ineffective) in the light of the Code. Here, we revise the nomenclature of ornithischian dinosaur clades; we revisit 76 preexisting ornithischian clade names, review their recent and historical use, and formally establish their phylogenetic definitions. Additionally, we introduce five new clade names: two for robustly supported clades of later-diverging hadrosaurids and ceratopsians, one uniting heterodontosaurids and genasaurs, and two for clades of nodosaurids. Our study marks a key step towards a formal phylogenetic nomenclature of ornithischian dinosaurs.

@article{doi107717peerj12362,
    author = "Madzia, Daniel and Arbour, Victoria M. and Boyd, Clint and Farke, Andrew A. and Cruzado‐Caballero, Penélope and Evans, David C.",
    title = "The phylogenetic nomenclature of ornithischian dinosaurs",
    year = "2021",
    journal = "PeerJ",
    abstract = "Ornithischians form a large clade of globally distributed Mesozoic dinosaurs, and represent one of their three major radiations. Throughout their evolutionary history, exceeding 134 million years, ornithischians evolved considerable morphological disparity, expressed especially through the cranial and osteodermal features of their most distinguishable representatives. The nearly two-century-long research history on ornithischians has resulted in the recognition of numerous diverse lineages, many of which have been named. Following the formative publications establishing the theoretical foundation of phylogenetic nomenclature throughout the 1980s and 1990s, many of the proposed names of ornithischian clades were provided with phylogenetic definitions. Some of these definitions have proven useful and have not been changed, beyond the way they were formulated, since their introduction. Some names, however, have multiple definitions, making their application ambiguous. Recent implementation of the International Code of Phylogenetic Nomenclature (ICPN, or PhyloCode) offers the opportunity to explore the utility of previously proposed definitions of established taxon names. Since the Articles of the ICPN are not to be applied retroactively, all phylogenetic definitions published prior to its implementation remain informal (and ineffective) in the light of the Code. Here, we revise the nomenclature of ornithischian dinosaur clades; we revisit 76 preexisting ornithischian clade names, review their recent and historical use, and formally establish their phylogenetic definitions. Additionally, we introduce five new clade names: two for robustly supported clades of later-diverging hadrosaurids and ceratopsians, one uniting heterodontosaurids and genasaurs, and two for clades of nodosaurids. Our study marks a key step towards a formal phylogenetic nomenclature of ornithischian dinosaurs.",
    url = "https://doi.org/10.7717/peerj.12362",
    doi = "10.7717/peerj.12362",
    openalex = "W4200166441",
    references = "crossref1998dinosaurs, doi101007s1254202100555w, doi101016jcretres2019104308, doi101016jcub201706071, doi101016jpalaeo201602033, doi101038s4158602030114, doi101038s41598020678541, doi101080027246342012694385, doi101080027246342013746229, doi1010800272463420181509866, doi1010800891296320201793979, doi1010801477201920151059985, doi1010801477201920171371258, doi101093sysbiosyab045, doi101098rsos161086, doi101098rspl18870117, doi101111pala12329, doi101111zoj12193, doi101126science28454232137, doi101139e11017, doi101146annureves23110192002313, doi101371journalpone0080405, doi101371journalpone0141304, doi101371journalpone0175253, doi101371journalpone0188426, doi1023071005355, doi1023071441916, doi1023072992353, doi102475ajss319111253, doi104202app006982019, doi104202app20110033, doi104202app20110051, doi105860choice353642, doi105860choice393984, doi105962bhltitle50608, doi107717peerj1523, doi107717peerj4066, doi107717peerj7963, openalexw568618627, tsogtbaatar2019a"
}

Modern birds are typified by the presence of feathers, complex evolutionary innovations that were already widespread in the group of theropod dinosaurs (Maniraptoriformes) that include crown Aves. Squamous or scaly reptilian-like skin is, however, considered the plesiomorphic condition for theropods and dinosaurs more broadly. Here, we review the morphology and distribution of non-feathered integumentary structures in non-avialan theropods, covering squamous skin and naked skin as well as dermal ossifications. The integumentary record of non-averostran theropods is limited to tracks, which ubiquitously show a covering of tiny reticulate scales on the plantar surface of the pes. This is consistent also with younger averostran body fossils, which confirm an arthral arrangement of the digital pads. Among averostrans, squamous skin is confirmed in Ceratosauria (Carnotaurus), Allosauroidea (Allosaurus, Concavenator, Lourinhanosaurus), Compsognathidae (Juravenator), and Tyrannosauroidea (Santanaraptor, Albertosaurus, Daspletosaurus, Gorgosaurus, Tarbosaurus, Tyrannosaurus), whereas dermal ossifications consisting of sagittate and mosaic osteoderms are restricted to Ceratosaurus. Naked, non-scale bearing skin is found in the contentious tetanuran Sciurumimus, ornithomimosaurians (Ornithomimus) and possibly tyrannosauroids (Santanaraptor), and also on the patagia of scansoriopterygids (Ambopteryx, Yi). Scales are surprisingly conservative among non-avialan theropods compared to some dinosaurian groups (e.g. hadrosaurids); however, the limited preservation of tegument on most specimens hinders further interrogation. Scale patterns vary among and/or within body regions in Carnotaurus, Concavenator and Juravenator, and include polarised, snake-like ventral scales on the tail of the latter two genera. Unusual but more uniformly distributed patterning also occurs in Tyrannosaurus, whereas feature scales are present only in Albertosaurus and Carnotaurus. Few theropods currently show compelling evidence for the co-occurrence of scales and feathers (e.g. Juravenator, Sinornithosaurus), although reticulate scales were probably retained on the mani and pedes of many theropods with a heavy plumage. Feathers and filamentous structures appear to have replaced widespread scaly integuments in maniraptorans. Theropod skin, and that of dinosaurs more broadly, remains a virtually untapped area of study and the appropriation of commonly used techniques in other palaeontological fields to the study of skin holds great promise for future insights into the biology, taphonomy and relationships of these extinct animals.

@article{doi101111brv12829,
    author = "Hendrickx, Christophe and Bell, Phil R. and Pittman, Michael and Milner, Andrew R. and Cuesta, Elena and O’Connor, Jingmai K. and Loewen, Mark A. and Currie, Philip J. and Mateus, Octávio and Kaye, Thomas G. and Delcourt, Rafael",
    title = "Morphology and distribution of scales, dermal ossifications, and other non‐feather integumentary structures in non‐avialan theropod dinosaurs",
    year = "2022",
    journal = "Biological reviews/Biological reviews of the Cambridge Philosophical Society",
    abstract = "Modern birds are typified by the presence of feathers, complex evolutionary innovations that were already widespread in the group of theropod dinosaurs (Maniraptoriformes) that include crown Aves. Squamous or scaly reptilian-like skin is, however, considered the plesiomorphic condition for theropods and dinosaurs more broadly. Here, we review the morphology and distribution of non-feathered integumentary structures in non-avialan theropods, covering squamous skin and naked skin as well as dermal ossifications. The integumentary record of non-averostran theropods is limited to tracks, which ubiquitously show a covering of tiny reticulate scales on the plantar surface of the pes. This is consistent also with younger averostran body fossils, which confirm an arthral arrangement of the digital pads. Among averostrans, squamous skin is confirmed in Ceratosauria (Carnotaurus), Allosauroidea (Allosaurus, Concavenator, Lourinhanosaurus), Compsognathidae (Juravenator), and Tyrannosauroidea (Santanaraptor, Albertosaurus, Daspletosaurus, Gorgosaurus, Tarbosaurus, Tyrannosaurus), whereas dermal ossifications consisting of sagittate and mosaic osteoderms are restricted to Ceratosaurus. Naked, non-scale bearing skin is found in the contentious tetanuran Sciurumimus, ornithomimosaurians (Ornithomimus) and possibly tyrannosauroids (Santanaraptor), and also on the patagia of scansoriopterygids (Ambopteryx, Yi). Scales are surprisingly conservative among non-avialan theropods compared to some dinosaurian groups (e.g. hadrosaurids); however, the limited preservation of tegument on most specimens hinders further interrogation. Scale patterns vary among and/or within body regions in Carnotaurus, Concavenator and Juravenator, and include polarised, snake-like ventral scales on the tail of the latter two genera. Unusual but more uniformly distributed patterning also occurs in Tyrannosaurus, whereas feature scales are present only in Albertosaurus and Carnotaurus. Few theropods currently show compelling evidence for the co-occurrence of scales and feathers (e.g. Juravenator, Sinornithosaurus), although reticulate scales were probably retained on the mani and pedes of many theropods with a heavy plumage. Feathers and filamentous structures appear to have replaced widespread scaly integuments in maniraptorans. Theropod skin, and that of dinosaurs more broadly, remains a virtually untapped area of study and the appropriation of commonly used techniques in other palaeontological fields to the study of skin holds great promise for future insights into the biology, taphonomy and relationships of these extinct animals.",
    url = "https://doi.org/10.1111/brv.12829",
    doi = "10.1111/brv.12829",
    openalex = "W4206485050",
    references = "crossref1998encyclopedia, doi101002jmor10382, doi101016jcub201706071, doi101016jcub202006105, doi101016jgca201006017, doi101016s001678780180047x, doi101017jpa202014, doi10103831635, doi10103834356, doi10103835047056, doi101038ncomms14972, doi101038s41598018371862, doi101038srep44942, doi1010800272463420211897604, doi101080147720192013781067, doi101093biolinneanblaa105, doi101093zoolinneanzly009, doi101111brv12829, doi101111cla12160, doi101126science28454232137, doi1011270077774920100125, doi101146annurevearth060313054858, doi1012063521, doi101371journalpone0044012, doi101371journalpone0125819, doi1017161paleo180818764, doi1017161pc180818764, doi10230725058147, doi105962bhltitle5716, doi107717peerj4066, doi107717peerj7247, doi107717peerj7963, doi107717peerj9192, erickson2014on, openalexw1915591379, openalexw2619609965"
}

@incollection{amils2023bioenergetics,
    author = "Amils, Ricardo",
    title = "Bioenergetics",
    year = "2023",
    booktitle = "Encyclopedia of Astrobiology",
    url = "https://doi.org/10.1007/978-3-662-65093-6\_746",
    doi = "10.1007/978-3-662-65093-6\_746",
    pages = "354-359"
}

Terrestrial environments pose many challenges to organisms, but perhaps one of the greatest is the need to breathe while maintaining water balance. Breathing air requires thin, moist respiratory surfaces, and thus the conditions necessary for gas exchange are also responsible for high rates of water loss that lead to desiccation. Across the diversity of terrestrial life, water loss acts as a universal cost of gas exchange and thus imposes limits on respiration. Amphibians are known for being vulnerable to rapid desiccation, in part because they rely on thin, permeable skin for cutaneous respiration. Yet, we have a limited understanding of the relationship between water loss and gas exchange within and among amphibian species. In this study, we evaluated the hydric costs of respiration in amphibians using the transpiration ratio, which is defined as the ratio of water loss (mol H2O d-1) to gas uptake (mol O2 d-1). A high ratio suggests greater hydric costs relative to the amount of gas uptake. We compared the transpiration ratio of amphibians with that of other terrestrial organisms to determine whether amphibians had greater hydric costs of gas uptake relative to plants, insects, birds, and mammals. We also evaluated the effects of temperature, humidity, and body mass on the transpiration ratio both within and among amphibian species. We found that hydric costs of respiration in amphibians were two to four orders of magnitude higher than the hydric costs of plants, insects, birds, and mammals. We also discovered that larger amphibians had lower hydric costs than smaller amphibians, at both the species- and individual-level. Amphibians also reduced the hydric costs of respiration at warm temperatures, potentially reflecting adaptive strategies to avoid dehydration while also meeting the demands of higher metabolic rates. Our results suggest that cutaneous respiration is an inefficient mode of respiration that produces the highest hydric costs of respiration yet to be measured in terrestrial plants and animals. Yet, amphibians largely avoid these costs by selecting aquatic or moist environments, which may facilitate more independent evolution of water loss and gas exchange.

@article{doi101093icbicae053,
    author = "Riddell, Eric A. and Burger, Isabella J. and Muñoz, Martha M. and Weaver, Savannah J. and Womack, Molly C.",
    title = "Amphibians Exhibit Extremely High Hydric Costs of Respiration",
    year = "2024",
    journal = "Integrative and Comparative Biology",
    abstract = "Terrestrial environments pose many challenges to organisms, but perhaps one of the greatest is the need to breathe while maintaining water balance. Breathing air requires thin, moist respiratory surfaces, and thus the conditions necessary for gas exchange are also responsible for high rates of water loss that lead to desiccation. Across the diversity of terrestrial life, water loss acts as a universal cost of gas exchange and thus imposes limits on respiration. Amphibians are known for being vulnerable to rapid desiccation, in part because they rely on thin, permeable skin for cutaneous respiration. Yet, we have a limited understanding of the relationship between water loss and gas exchange within and among amphibian species. In this study, we evaluated the hydric costs of respiration in amphibians using the transpiration ratio, which is defined as the ratio of water loss (mol H2O d-1) to gas uptake (mol O2 d-1). A high ratio suggests greater hydric costs relative to the amount of gas uptake. We compared the transpiration ratio of amphibians with that of other terrestrial organisms to determine whether amphibians had greater hydric costs of gas uptake relative to plants, insects, birds, and mammals. We also evaluated the effects of temperature, humidity, and body mass on the transpiration ratio both within and among amphibian species. We found that hydric costs of respiration in amphibians were two to four orders of magnitude higher than the hydric costs of plants, insects, birds, and mammals. We also discovered that larger amphibians had lower hydric costs than smaller amphibians, at both the species- and individual-level. Amphibians also reduced the hydric costs of respiration at warm temperatures, potentially reflecting adaptive strategies to avoid dehydration while also meeting the demands of higher metabolic rates. Our results suggest that cutaneous respiration is an inefficient mode of respiration that produces the highest hydric costs of respiration yet to be measured in terrestrial plants and animals. Yet, amphibians largely avoid these costs by selecting aquatic or moist environments, which may facilitate more independent evolution of water loss and gas exchange.",
    url = "https://doi.org/10.1093/icb/icae053",
    doi = "10.1093/icb/icae053",
    openalex = "W4399102633",
    references = "doi101002j204046032013tb00502x"
}

@incollection{alexanderNoneenergetics,
    author = "Alexander, David E.",
    title = "Energetics, ecological (bioenergetics)",
    year = "None",
    booktitle = "Encyclopedia of Earth Science",
    url = "https://doi.org/10.1007/1-4020-4494-1\_107",
    doi = "10.1007/1-4020-4494-1\_107",
    openalex = "W4302611622",
    pages = "186-187"
}