Computer methods

@article{dart1934the,
    author = "Dart, Raymond A.",
    title = "The Dentition of Australopithecus Africanus.",
    year = "1934",
    journal = "Folia Anatomica Japonica",
    url = "https://doi.org/10.2535/ofaj1922.12.4\_207",
    doi = "10.2535/ofaj1922.12.4\_207",
    number = "4",
    pages = "207-221\_5",
    volume = "12"
}

The earliest hominid from South Africa, Australopithecus africanus, is known from only six specimens in which accurate assessment of endocranial capacity and cranial venous outflow pattern can be obtained. This places a severe limit on a number of hypotheses concerning early hominid evolution, particularly those involving brain-body size relationships and adaptations of the circulatory system to evolving upright posture. Advances in high-resolution two- and three-dimensional computed tomography (CT) now allow the inclusion of another important specimen to this list, MLD 37/38 from Makapansgat. A new computer imaging technique is described that "reconstructs" the missing portions of the endocranial cavity in order to determine endocranial capacity. In addition, CT evaluation allows assessment of cranial venous outflow pattern even in cases where the endocranial cavity is completely filled with stone matrix. Results show that endocranial capacity in this specimen is less than originally proposed and also support the view that gracile and robust australopithecines evolved different cranial venous outflow patterns in response to upright postures.

@article{conroy1990endocranial,
    author = "Conroy, Glenn C. and Vannier, Michael W. and Tobias, Phillip V.",
    title = "Endocranial Features of Australopithecus africanus Revealed by 2- and 3-D Computed Tomography",
    year = "1990",
    journal = "Science",
    abstract = {The earliest hominid from South Africa, Australopithecus africanus, is known from only six specimens in which accurate assessment of endocranial capacity and cranial venous outflow pattern can be obtained. This places a severe limit on a number of hypotheses concerning early hominid evolution, particularly those involving brain-body size relationships and adaptations of the circulatory system to evolving upright posture. Advances in high-resolution two- and three-dimensional computed tomography (CT) now allow the inclusion of another important specimen to this list, MLD 37/38 from Makapansgat. A new computer imaging technique is described that "reconstructs" the missing portions of the endocranial cavity in order to determine endocranial capacity. In addition, CT evaluation allows assessment of cranial venous outflow pattern even in cases where the endocranial cavity is completely filled with stone matrix. Results show that endocranial capacity in this specimen is less than originally proposed and also support the view that gracile and robust australopithecines evolved different cranial venous outflow patterns in response to upright postures.},
    url = "https://doi.org/10.1126/science.2305255",
    doi = "10.1126/science.2305255",
    number = "4944",
    pages = "838-841",
    volume = "247"
}

@misc{conway1990endocranial1,
    author = "Conway, G. C. and Vannier, M. W. and Tobias, P. V",
    title = "Endocranial features of Australopithecus africanus revealed by 2- and 3-D computed tomography",
    year = "1990",
    howpublished = "Science, v. 247, p. 838",
    note = "talkorigins\_source = {true}; raw\_reference = {Conway, G. C., Vannier, M. W., and Tobias, P. V., 1990, Endocranial features of Australopithecus africanus revealed by 2- and 3-D computed tomography: Science, v. 247, p. 838.}"
}

The earliest hominid from South Africa, Australopithecus africanus, is known from only six specimens in which accurate assessment of endocranial capacity and cranial venous outflow pattern can be obtained. This places a severe limit on a number of hypotheses concerning early hominid evolution, particularly those involving brain-body size relationships and adaptations of the circulatory system to evolving upright posture. Advances in high-resolution two- and three-dimensional computed tomography (CT) now allow the inclusion of another important specimen to this list, MLD 37/38 from Makapansgat. A new computer imaging technique is described that "reconstructs" the missing portions of the endocranial cavity in order to determine endocranial capacity. In addition, CT evaluation allows assessment of cranial venous outflow pattern even in cases where the endocranial cavity is completely filled with stone matrix. Results show that endocranial capacity in this specimen is less than originally proposed and also support the view that gracile and robust australopithecines evolved different cranial venous outflow patterns in response to upright postures.

@article{doi101126science2305255,
    author = "Conroy, G C and Vannier, M W and Tobias, P V",
    title = "Endocranial features of Australopithecus africanus revealed by 2- and 3-D computed tomography.",
    year = "1990",
    journal = "Science (New York, N.Y.)",
    abstract = {The earliest hominid from South Africa, Australopithecus africanus, is known from only six specimens in which accurate assessment of endocranial capacity and cranial venous outflow pattern can be obtained. This places a severe limit on a number of hypotheses concerning early hominid evolution, particularly those involving brain-body size relationships and adaptations of the circulatory system to evolving upright posture. Advances in high-resolution two- and three-dimensional computed tomography (CT) now allow the inclusion of another important specimen to this list, MLD 37/38 from Makapansgat. A new computer imaging technique is described that "reconstructs" the missing portions of the endocranial cavity in order to determine endocranial capacity. In addition, CT evaluation allows assessment of cranial venous outflow pattern even in cases where the endocranial cavity is completely filled with stone matrix. Results show that endocranial capacity in this specimen is less than originally proposed and also support the view that gracile and robust australopithecines evolved different cranial venous outflow patterns in response to upright postures.},
    url = "https://pubmed.ncbi.nlm.nih.gov/2305255/",
    doi = "10.1126/science.2305255",
    pmid = "2305255"
}

Until recently, it has not been possible to systematically study enamel thickness in fossil hominids except by physically sectioning the teeth. Because sectioning studies destroy original specimens, sample sizes will always be low. For this reason, anthropologists have had to devise other methods for acquiring these data such as by measuring enamel in naturally fractured teeth or where it is exposed in worn teeth. It is clearly important to develop and apply non-invasive techniques to augment and expand the data base of early hominid enamel thickness. This is a first attempt to provide such data for a sample of South African australopithecines by utilizing high-resolution computed tomography (CT). This study is based on over 130 CT scans taken at 1 mm slice thickness on a sample of 22 original Australopithecus africanus and A. robustus lower molars from Sterkfontein, Kromdraai, Makapansgat, Swartkrans and Taung. Mean values of absolute and relative enamel thickness between A. africanus and A. robustus are significantly different, confirming that robust australopithecines have thicker enamel than their gracile counterparts. CT sections were taken in the buccolingual plane through the mesial cusps (protoconid, metaconid). While the mean value of enamel thickness at the buccal cusp (protoconid) is greater in A. robustus than in A. africanus, the difference is not statistically significant. The difference in enamel thickness at the lingual cusp (metaconid) is statistically significant, however. This study represents an important, albeit preliminary, first step in establishing a methodology for the non-invasive evaluation of enamel thickness in fossil hominids by computed tomography. It demonstrates the viability of the technique and the type of problem oriented approach that can be tackled using computed tomography in modem anthropological research. Measurements derived from CT cannot, of course, be expected to have the same degree of precision as those taken directly from sectioned teeth; nevertheless, important insights into the functional morphology of early hominid teeth are still easily decipherable from the CT data. Given that the alternative to CT is the physical destruction of original hominid fossils, the slight loss in mensurational accuracy seems well worth the price.

@article{openalexw2098165476,
    author = "Conroy, Glenn C.",
    title = "Enamel thickness in South African australopithecines: noninvasive evaluation by computed tomography",
    year = "1991",
    journal = "University of the Witwatersrand, Johannesburg Institutional Repository on DSpace (University of the Witwatersrand, Johannesburg)",
    abstract = "Until recently, it has not been possible to systematically study enamel thickness in fossil hominids except by physically sectioning the teeth. Because sectioning studies destroy original specimens, sample sizes will always be low. For this reason, anthropologists have had to devise other methods for acquiring these data such as by measuring enamel in naturally fractured teeth or where it is exposed in worn teeth. It is clearly important to develop and apply non-invasive techniques to augment and expand the data base of early hominid enamel thickness. This is a first attempt to provide such data for a sample of South African australopithecines by utilizing high-resolution computed tomography (CT). This study is based on over 130 CT scans taken at 1 mm slice thickness on a sample of 22 original Australopithecus africanus and A. robustus lower molars from Sterkfontein, Kromdraai, Makapansgat, Swartkrans and Taung. Mean values of absolute and relative enamel thickness between A. africanus and A. robustus are significantly different, confirming that robust australopithecines have thicker enamel than their gracile counterparts. CT sections were taken in the buccolingual plane through the mesial cusps (protoconid, metaconid). While the mean value of enamel thickness at the buccal cusp (protoconid) is greater in A. robustus than in A. africanus, the difference is not statistically significant. The difference in enamel thickness at the lingual cusp (metaconid) is statistically significant, however. This study represents an important, albeit preliminary, first step in establishing a methodology for the non-invasive evaluation of enamel thickness in fossil hominids by computed tomography. It demonstrates the viability of the technique and the type of problem oriented approach that can be tackled using computed tomography in modem anthropological research. Measurements derived from CT cannot, of course, be expected to have the same degree of precision as those taken directly from sectioned teeth; nevertheless, important insights into the functional morphology of early hominid teeth are still easily decipherable from the CT data. Given that the alternative to CT is the physical destruction of original hominid fossils, the slight loss in mensurational accuracy seems well worth the price.",
    url = "https://openalex.org/W2098165476",
    openalex = "W2098165476",
    references = "doi101002ajpa1330460310, doi101002ajpa1330550202, doi101002ajpa1330700205, doi101038314260a0, doi101038329625a0, doi101126science2264673456, doi104324978131512740848, openalexw1516188323, openalexw2987799915, openalexw3034932225"
}

Current consensus holds that the 3-million-year-old hominid Australopithecus africanus subsisted on fruits and leaves, much as the modern chimpanzee does. Stable carbon isotope analysis of A. africanus from Makapansgat Limeworks, South Africa, demonstrates that this early hominid ate not only fruits and leaves but also large quantities of carbon-13-enriched foods such as grasses and sedges or animals that ate these plants, or both. The results suggest that early hominids regularly exploited relatively open environments such as woodlands or grasslands for food. They may also suggest that hominids consumed high-quality animal foods before the development of stone tools and the origin of the genus Homo.

@article{doi101126science2835400368,
    author = "Sponheimer, Matt and Lee‐Thorp, Julia A.",
    title = "Isotopic Evidence for the Diet of an Early Hominid, Australopithecus africanus",
    year = "1999",
    journal = "Science",
    abstract = "Current consensus holds that the 3-million-year-old hominid Australopithecus africanus subsisted on fruits and leaves, much as the modern chimpanzee does. Stable carbon isotope analysis of A. africanus from Makapansgat Limeworks, South Africa, demonstrates that this early hominid ate not only fruits and leaves but also large quantities of carbon-13-enriched foods such as grasses and sedges or animals that ate these plants, or both. The results suggest that early hominids regularly exploited relatively open environments such as woodlands or grasslands for food. They may also suggest that hominids consumed high-quality animal foods before the development of stone tools and the origin of the genus Homo.",
    url = "https://doi.org/10.1126/science.283.5400.368",
    doi = "10.1126/science.283.5400.368",
    openalex = "W2081962176",
    references = "doi101017cbo9780511897795"
}

@article{conroy2000endocranial,
    author = "Conroy, Glenn C. and Falk, Dean and Guyer, John and Weber, Gerhard W. and Seidler, Horst and Recheis, Wolfgang",
    title = "Endocranial capacity in Sts 71 (Australopithecus africanus) by three-dimensional computed tomography",
    year = "2000",
    journal = "The Anatomical Record",
    url = "https://doi.org/10.1002/(sici)1097-0185(20000401)258:4<391::aid-ar7>3.0.co;2-r",
    doi = "10.1002/(sici)1097-0185(20000401)258:4<391::aid-ar7>3.0.co;2-r",
    number = "4",
    pages = "391-396",
    volume = "258"
}

@article{doi101023a1009417831601,
    author = "Marino, Lori and Uhen, Mark D. and Frøhlich, Bruno and Aldag, J. Matthew and Blane, Caroline E. and Bohaska, David J. and Whitmore, Frank C.",
    title = "Endocranial Volume of Mid-Late Eocene Archaeocetes (Order: Cetacea) Revealed by Computed Tomography: Implications for Cetacean Brain Evolution",
    year = "2000",
    journal = "Journal of Mammalian Evolution",
    url = "https://doi.org/10.1023/a:1009417831601",
    doi = "10.1023/a:1009417831601",
    openalex = "W1508094836",
    references = "doi101002sici1520650519965381aidevan330co2z, doi101016s0169534798013263, doi101126science2264673456, doi101159000006540, doi1023071374291, doi1023072407154, openalexw1589958201, openalexw589017531, openalexw61293311"
}

@article{doi10100210982353200103142134aidca102130co2f,
    author = "Tobias, P.",
    title = "Re‐creating ancient hominid virtual endocasts by CT‐scanning",
    year = "2001",
    journal = "Clinical Anatomy",
    url = "https://www.semanticscholar.org/paper/6bb67dfb00c6eba5b7eccf7c99b659ee4d5664ce",
    doi = "10.1002/1098-2353(200103)14:2<134::AID-CA1021>3.0.CO;2-F",
    is_oa = "true",
    number = "2",
    pages = "134-141",
    semanticscholar_citation_count = "36",
    semanticscholar_id = "6bb67dfb00c6eba5b7eccf7c99b659ee4d5664ce",
    volume = "14"
}

Dart's 1925 announcement of Australopithecus africanus (Dart: Nature 115 [1925] 195-199) was highly controversial, partly because of an interpretation of the Taung natural endocast that rested on an erroneous identification of the lambdoid suture as the lunate sulcus. Unpublished materials from the University of Witwatersrand Archives (Dart, unpublished material) reveal that Dart reacted to the controversy by: 1) describing and illustrating the entire sulcal pattern on the Taung endocast, in contrast to just two sulcal identifications in 1925, 2) identifying a hypothetical part of the lambdoid suture and revising his description of the lunate sulcus, and 3) bolstering his argument that Taung's brain was advanced by detailing expansions in three significant cortical association areas. Four unpublished illustrations of Dart's identifications for sulci and sutures on the Taung endocast are compared here with those published by Keith (Keith: New discoveries relating to the antiquity of man (1931)), Schepers (Schepers: The endocranial casts of the South African ape-men. In: Broom R, Schepers GWH, editors. The South African fossil ape-men; the Australopithecinae [1946] p 155-272), and Falk (Falk: Am J Phys Anthropol 53 [1980] 525-539), and the thorny issue of the location of the lunate sulcus is revisited in light of new information. Archival materials reveal that Dart believed that Taung's brain was reorganized globally rather than in a mosaic manner, and that the shapes of certain cortical association areas showed that Australopithecus was closer to Pithecanthropus than to the living apes. Although a few of Dart's hitherto-unpublished sulcal identifications, including his revision for the lunate sulcus, were questionable, his claim that the Taung endocast reproduced a shape that was advanced toward a human condition in its prefrontal cortex and caudally protruded occipital lobe was correct.

@article{doi101002ajpa21184,
    author = "Falk, Dean",
    title = "The natural endocast of Taung (Australopithecus africanus): Insights from the unpublished papers of Raymond Arthur Dart",
    year = "2009",
    journal = "American Journal of Physical Anthropology",
    abstract = "Dart's 1925 announcement of Australopithecus africanus (Dart: Nature 115 [1925] 195-199) was highly controversial, partly because of an interpretation of the Taung natural endocast that rested on an erroneous identification of the lambdoid suture as the lunate sulcus. Unpublished materials from the University of Witwatersrand Archives (Dart, unpublished material) reveal that Dart reacted to the controversy by: 1) describing and illustrating the entire sulcal pattern on the Taung endocast, in contrast to just two sulcal identifications in 1925, 2) identifying a hypothetical part of the lambdoid suture and revising his description of the lunate sulcus, and 3) bolstering his argument that Taung's brain was advanced by detailing expansions in three significant cortical association areas. Four unpublished illustrations of Dart's identifications for sulci and sutures on the Taung endocast are compared here with those published by Keith (Keith: New discoveries relating to the antiquity of man (1931)), Schepers (Schepers: The endocranial casts of the South African ape-men. In: Broom R, Schepers GWH, editors. The South African fossil ape-men; the Australopithecinae [1946] p 155-272), and Falk (Falk: Am J Phys Anthropol 53 [1980] 525-539), and the thorny issue of the location of the lunate sulcus is revisited in light of new information. Archival materials reveal that Dart believed that Taung's brain was reorganized globally rather than in a mosaic manner, and that the shapes of certain cortical association areas showed that Australopithecus was closer to Pithecanthropus than to the living apes. Although a few of Dart's hitherto-unpublished sulcal identifications, including his revision for the lunate sulcus, were questionable, his claim that the Taung endocast reproduced a shape that was advanced toward a human condition in its prefrontal cortex and caudally protruded occipital lobe was correct.",
    url = "https://doi.org/10.1002/ajpa.21184",
    doi = "10.1002/ajpa.21184",
    openalex = "W1972956224",
    references = "dart1934the"
}

Humans show a unique pattern of brain growth that differentiates us from all other primates. In this study, we use virtual endocasts to provide a detailed description of shape changes during human postnatal ontogeny with geometric morphometric methods. Using CT scans of 108 dried human crania ranging in age from newborns to adults and several hundred landmarks and semi-landmarks, we find that the endocranial ontogenetic trajectory is curvilinear with two bends, separating three distinct phases of shape change. We test to what extent endocranial shape change is driven by size increase and whether the curved ontogenetic trajectory can be explained by a simple model of modular development of the endocranial base and the endocranial vault. The hypothesis that endocranial shape change is driven exclusively by brain growth is not supported; we find changes in endocranial shape after adult size has been attained and that the transition from high rates to low rates of size increase does not correspond to one of the shape trajectory bends. The ontogenetic trajectory of the endocranial vault analyzed separately is nearly linear; the trajectory of the endocranial base, in contrast, is curved. The endocranial vault therefore acts as one developmental module during human postnatal ontogeny. Our data suggest that the cranial base comprises several submodules that follow their own temporally and/or spatially disjunct growth trajectories.

@article{doi101111j14697580200901106x,
    author = "Neubauer, Simon and Gunz, Philipp and Hublin, Jean‐Jacques",
    title = "The pattern of endocranial ontogenetic shape changes in humans",
    year = "2009",
    journal = "Journal of Anatomy",
    abstract = "Humans show a unique pattern of brain growth that differentiates us from all other primates. In this study, we use virtual endocasts to provide a detailed description of shape changes during human postnatal ontogeny with geometric morphometric methods. Using CT scans of 108 dried human crania ranging in age from newborns to adults and several hundred landmarks and semi-landmarks, we find that the endocranial ontogenetic trajectory is curvilinear with two bends, separating three distinct phases of shape change. We test to what extent endocranial shape change is driven by size increase and whether the curved ontogenetic trajectory can be explained by a simple model of modular development of the endocranial base and the endocranial vault. The hypothesis that endocranial shape change is driven exclusively by brain growth is not supported; we find changes in endocranial shape after adult size has been attained and that the transition from high rates to low rates of size increase does not correspond to one of the shape trajectory bends. The ontogenetic trajectory of the endocranial vault analyzed separately is nearly linear; the trajectory of the endocranial base, in contrast, is curved. The endocranial vault therefore acts as one developmental module during human postnatal ontogeny. Our data suggest that the cranial base comprises several submodules that follow their own temporally and/or spatially disjunct growth trajectories.",
    url = "https://doi.org/10.1111/j.1469-7580.2009.01106.x",
    doi = "10.1111/j.1469-7580.2009.01106.x",
    openalex = "W2039753011",
    references = "conroy1990endocranial, conroy2000endocranial, doi101007bf02291478, doi101016s1361841597850128, doi101017cbo9780511573064, doi10103813158, doi101038142004a0, doi101109tpami200586, doi1023072532725, doi1023072992207, openalexw2506868775"
}

International audience

@article{s2d8e5f997314c6c400b29a7d9fa6e774717368ac4,
    author = "Braga, J. and Thackeray, F. and Subsol, G. and Treil, J. and Dasgupta, G.",
    title = "Important variations in dental trait expression at the EDJ throughout an Australopithecus africanus entire postcanine dentition",
    year = "2009",
    journal = "HAL (Le Centre pour la Communication Scientifique Directe)",
    abstract = "International audience",
    url = "https://www.semanticscholar.org/paper/d8e5f997314c6c400b29a7d9fa6e774717368ac4",
    is_oa = "true",
    openalex = "W2739071118",
    semanticscholar_id = "d8e5f997314c6c400b29a7d9fa6e774717368ac4"
}

@article{doi101002ajpa21276,
    author = "Sylvester, A.",
    title = "Asymmetry in Saguinus oedipus limb bone dimensions",
    year = "2010",
    journal = "American Journal of Physical Anthropology",
    url = "https://onlinelibrary.wiley.com/doi/pdfdirect/10.1002/ajpa.21276",
    doi = "10.1002/AJPA.21276",
    is_oa = "true",
    number = "S50",
    pages = "52-252",
    semanticscholar_citation_count = "1",
    semanticscholar_id = "5d8dfcf99fda47102040128c34a10227bed2d7c7",
    volume = "141"
}

Despite a rich African Plio-Pleistocene hominin fossil record, the ancestry of Homo and its relation to earlier australopithecines remain unresolved. Here we report on two partial skeletons with an age of 1.95 to 1.78 million years. The fossils were encased in cave deposits at the Malapa site in South Africa. The skeletons were found close together and are directly associated with craniodental remains. Together they represent a new species of Australopithecus that is probably descended from Australopithecus africanus. Combined craniodental and postcranial evidence demonstrates that this new species shares more derived features with early Homo than any other australopith species and thus might help reveal the ancestor of that genus.

@article{doi101126science1184944,
    author = "Berger, Lee R. and de Ruiter, Darryl J. and Churchill, Steven E. and Schmid, Peter and Carlson, Kristian J. and Dirks, Paul H.G.M. and Kibii, Job M.",
    title = "Australopithecus sediba: A New Species of Homo -Like Australopith from South Africa",
    year = "2010",
    journal = "Science",
    abstract = "Despite a rich African Plio-Pleistocene hominin fossil record, the ancestry of Homo and its relation to earlier australopithecines remain unresolved. Here we report on two partial skeletons with an age of 1.95 to 1.78 million years. The fossils were encased in cave deposits at the Malapa site in South Africa. The skeletons were found close together and are directly associated with craniodental remains. Together they represent a new species of Australopithecus that is probably descended from Australopithecus africanus. Combined craniodental and postcranial evidence demonstrates that this new species shares more derived features with early Homo than any other australopith species and thus might help reveal the ancestor of that genus.",
    url = "https://doi.org/10.1126/science.1184944",
    doi = "10.1126/science.1184944",
    openalex = "W2105844813",
    references = "doi101002ajpa1330600302, doi101016c2009002515x, doi101038115195a0, doi101038327205a0, doi10103835068500, doi101038373509a0, doi101038nature03052, doi101126science284541165, doi101126science2845414629, doi105962bhltitle15880, johanson1979a"
}

@article{doi101016jjhevol201201005,
    author = "Neubauer, Simon and Gunz, Philipp and Weber, Gerhard W. and Hublin, Jean‐Jacques",
    title = "Endocranial volume of Australopithecus africanus: New CT-based estimates and the effects of missing data and small sample size",
    year = "2012",
    journal = "Journal of Human Evolution",
    url = "https://doi.org/10.1016/j.jhevol.2012.01.005",
    doi = "10.1016/j.jhevol.2012.01.005",
    openalex = "W2004358325",
    references = "conroy2000endocranial"
}

The type specimen for Australopithecus africanus (Taung) includes a natural endocast that reproduces most of the external morphology of the right cerebral hemisphere and a fragment of fossilized face that articulates with the endocast. Despite the fact that Taung died between 3 and 4 y of age, the endocast reproduces a small triangular-shaped remnant of the anterior fontanelle, from which a clear metopic suture (MS) courses rostrally along the midline [Hrdlička A (1925) Am J Phys Anthropol 8:379-392]. Here we describe and interpret this feature of Taung in light of comparative fossil and actualistic data on the timing of MS closure. In great apes, the MS normally fuses shortly after birth, such that unfused MS similar to Taung's are rare. In humans, however, MS fuses well after birth, and partially or unfused MS are frequent. In gracile fossil adult hominins that lived between ∼3.0 and 1.5 million y ago, MS are also relatively frequent, indicating that the modern human-like pattern of late MS fusion may have become adaptive during early hominin evolution. Selective pressures favoring delayed fusion might have resulted from three aspects of perinatal ontogeny: (i) the difficulty of giving birth to large-headed neonates through birth canals that were reconfigured for bipedalism (the "obstetric dilemma"), (ii) high early postnatal brain growth rates, and (iii) reorganization and expansion of the frontal neocortex. Overall, our data indicate that hominin brain evolution occurred within a complex network of fetopelvic constraints, which required modification of frontal neurocranial ossification patterns.

@article{doi101073pnas1119752109,
    author = "Falk, Dean and Zollikofer, Christoph P. E. and Morimoto, Naoki and de León, Marcia S. Ponce",
    title = "Metopic suture of Taung (Australopithecus africanus) and its implications for hominin brain evolution",
    year = "2012",
    journal = "Proceedings of the National Academy of Sciences",
    abstract = {The type specimen for Australopithecus africanus (Taung) includes a natural endocast that reproduces most of the external morphology of the right cerebral hemisphere and a fragment of fossilized face that articulates with the endocast. Despite the fact that Taung died between 3 and 4 y of age, the endocast reproduces a small triangular-shaped remnant of the anterior fontanelle, from which a clear metopic suture (MS) courses rostrally along the midline [Hrdlička A (1925) Am J Phys Anthropol 8:379-392]. Here we describe and interpret this feature of Taung in light of comparative fossil and actualistic data on the timing of MS closure. In great apes, the MS normally fuses shortly after birth, such that unfused MS similar to Taung's are rare. In humans, however, MS fuses well after birth, and partially or unfused MS are frequent. In gracile fossil adult hominins that lived between ∼3.0 and 1.5 million y ago, MS are also relatively frequent, indicating that the modern human-like pattern of late MS fusion may have become adaptive during early hominin evolution. Selective pressures favoring delayed fusion might have resulted from three aspects of perinatal ontogeny: (i) the difficulty of giving birth to large-headed neonates through birth canals that were reconfigured for bipedalism (the "obstetric dilemma"), (ii) high early postnatal brain growth rates, and (iii) reorganization and expansion of the frontal neocortex. Overall, our data indicate that hominin brain evolution occurred within a complex network of fetopelvic constraints, which required modification of frontal neurocranial ossification patterns.},
    url = "https://doi.org/10.1073/pnas.1119752109",
    doi = "10.1073/pnas.1119752109",
    openalex = "W2125378137",
    references = "doi101126science1683934966"
}