Crustacea

@article{ulrich1931cambrian,
    author = "Ulrich, E. O. and Bassler, Ray S.",
    title = "Cambrian bivalved Crustacea of the order Conchostraca",
    year = "1931",
    journal = "Proceedings of the United States National Museum",
    url = "https://doi.org/10.5479/si.00963801.78-2847.1",
    doi = "10.5479/si.00963801.78-2847.1",
    number = "2847",
    openalex = "W2038299230",
    pages = "1-130",
    volume = "78"
}

@techreport{glaessner1960the1,
    author = "Glaessner, M. F",
    title = "The fossil decapod Crustacea of New Zealand and the evolution of the order Decapoda",
    year = "1960",
    howpublished = "New Zealand Geological Survey, Paleontological Bulletin, v. 31, p. 1-63",
    note = "talkorigins\_source = {true}; raw\_reference = {Glaessner, M. F., 1960, The fossil decapod Crustacea of New Zealand and the evolution of the order Decapoda: New Zealand Geological Survey, Paleontological Bulletin, v. 31, p. 1-63.}"
}

@misc{glaessner1969decapoda2,
    author = "Glaessner, M. F",
    title = "Decapoda, p. R399-R533, in Moore, R. C., ed., Treatise on Invertebrate Paleontology",
    year = "1969",
    howpublished = "v. 2, p. R399-R651",
    note = "talkorigins\_source = {true}; raw\_reference = {Glaessner, M. F., 1969, Decapoda, p. R399-R533, in Moore, R. C., ed., Treatise on Invertebrate Paleontology: v. 2, p. R399-R651.}"
}

@article{gruber1971problems3,
    author = "Gruber, A. L",
    title = "Problems of sexual dimorphism, population structure and taxonomy of the Ordovician genus Tetradella (Ostracoda)",
    year = "1971",
    journal = "Journal of Paleontology, v. 45, p. 6-22",
    note = "talkorigins\_source = {true}; raw\_reference = {Gruber, A. L., 1971, Problems of sexual dimorphism, population structure and taxonomy of the Ordovician genus Tetradella (Ostracoda): Journal of Paleontology, v. 45, p. 6-22.}"
}

Mülkr. Klaus 1. 1979 01 IS: Phosphatocopine ostracodes with preserved appendages from the Upper Cambrian of Sweden. Lethaia. Vol. 12. pp. 1–27. Oslo. ISSN 0024–1164. More than 400 specimens of phosphatocopine ostracodes. representing different moult stages of Vestrogothia. Falites and Hesslandona have been recovered, with body and appendage structures preserved in minute detail. from anthraconites in the Upper Cambrian of Sweden and drift boulders deriving from that area. The secondary phosphatization of these structures, leading to preservation. is extensively discussed. It comprises even the inner lamella, but the abdomen is not preserved. Hypostome and lower lip are well developed. The large antennula is composed of a basipodite with probably two podomeres and a long exopodite with up to 18 podomeres bearing long spines, forming a natatory organ, and a broad endopodite of two to three podomeres. The biramous organization of the antennula is a unique, most primitive feature of phylogenetic significance. The antennae and up lo four additional pairs of appendages are also biramous and similar to the antennulae, not yet differentiated for specialized functions. Only the last pair is uniramous, but a second branch may have developed in subsequent moult stages not represented in the material. The movement of food into the mouth was achieved by the endites of antennulae and antennae, a function transferred backwards to other appendages during the course of ostracode phylogeny and reflected in ontogenetic trends among Recent ostracodes. The phosphatocopines were nectobenthic, filtering plankton feeders.

@article{doi101111j150239311979tb01234x,
    author = "Müller, Klaus J.",
    title = "Phosphatocopine ostracodes with preserved appendages from the Upper Cambrian of Sweden",
    year = "1979",
    journal = "Lethaia",
    abstract = "Mülkr. Klaus 1. 1979 01 IS: Phosphatocopine ostracodes with preserved appendages from the Upper Cambrian of Sweden. Lethaia. Vol. 12. pp. 1–27. Oslo. ISSN 0024–1164. More than 400 specimens of phosphatocopine ostracodes. representing different moult stages of Vestrogothia. Falites and Hesslandona have been recovered, with body and appendage structures preserved in minute detail. from anthraconites in the Upper Cambrian of Sweden and drift boulders deriving from that area. The secondary phosphatization of these structures, leading to preservation. is extensively discussed. It comprises even the inner lamella, but the abdomen is not preserved. Hypostome and lower lip are well developed. The large antennula is composed of a basipodite with probably two podomeres and a long exopodite with up to 18 podomeres bearing long spines, forming a natatory organ, and a broad endopodite of two to three podomeres. The biramous organization of the antennula is a unique, most primitive feature of phylogenetic significance. The antennae and up lo four additional pairs of appendages are also biramous and similar to the antennulae, not yet differentiated for specialized functions. Only the last pair is uniramous, but a second branch may have developed in subsequent moult stages not represented in the material. The movement of food into the mouth was achieved by the endites of antennulae and antennae, a function transferred backwards to other appendages during the course of ostracode phylogeny and reflected in ontogenetic trends among Recent ostracodes. The phosphatocopines were nectobenthic, filtering plankton feeders.",
    url = "https://doi.org/10.1111/j.1502-3931.1979.tb01234.x",
    doi = "10.1111/j.1502-3931.1979.tb01234.x",
    openalex = "W2099466022",
    references = "doi101002mmnz19670430221, doi101007bf02989626, doi101016b9780444826725500040, doi101126science1533732167, doi101127zdgg1111959434, doi101130mem59p1, doi1023071484753, doi1023071540077, openalexw226181322, openalexw653061531"
}

@misc{muller1983crustacea4,
    author = "Muller, K. J",
    title = "Crustacea with preserved soft parts from the Upper Cambrian of Sweden",
    year = "1983",
    howpublished = "Lethaia, v. 16, p. 93-109",
    note = "talkorigins\_source = {true}; raw\_reference = {Muller, K. J., 1983, Crustacea with preserved soft parts from the Upper Cambrian of Sweden: Lethaia, v. 16, p. 93-109.}"
}

@article{müller1983crustacea,
    author = "Müller, Klaus J.",
    title = "Crustacea with preserved soft parts from the Upper Cambrian of Sweden",
    year = "1983",
    journal = "Lethaia",
    url = "https://doi.org/10.1111/j.1502-3931.1983.tb01704.x",
    doi = "10.1111/j.1502-3931.1983.tb01704.x",
    number = "2",
    pages = "93-109",
    volume = "16"
}

@misc{muller1984skaracaridae5,
    author = "Muller, K. J. and Walossek, D",
    title = "Skaracaridae, a new order of Crustacea from the Upper Cambrian of Vstergtland, Sweden",
    year = "1984",
    howpublished = "Fossils and Strata (Oslo), v. 17, p. 1-65",
    note = "talkorigins\_source = {true}; raw\_reference = {Muller, K. J., and Walossek, D., 1984, Skaracaridae, a new order of Crustacea from the Upper Cambrian of Vstergtland, Sweden: Fossils and Strata (Oslo), v. 17, p. 1-65.}"
}

ABSTRACT Extensive preparation since 1975 has yielded thousands of specimens of various minute arthropods, mainly phosphatocopid ostracods and other crustaceans. The whole exoskeleton is exceedingly well preserved in three dimensions, showing even delicate mo1 phological details. The material permits not only the description of the morphology and systematic status of the animals but also interpretation, with a high degree of confidence, of the function, life habit, and ontogeny of these early arthropods.

@article{doi101017s0263593300010427,
    author = "Müller, Klaus J. and Waloßek, Dieter",
    title = "A remarkable arthropod fauna from the Upper Cambrian “Orsten” of Sweden",
    year = "1985",
    journal = "Earth and Environmental Science Transactions of the Royal Society of Edinburgh",
    abstract = "ABSTRACT Extensive preparation since 1975 has yielded thousands of specimens of various minute arthropods, mainly phosphatocopid ostracods and other crustaceans. The whole exoskeleton is exceedingly well preserved in three dimensions, showing even delicate mo1 phological details. The material permits not only the description of the morphology and systematic status of the animals but also interpretation, with a high degree of confidence, of the function, life habit, and ontogeny of these early arthropods.",
    url = "https://doi.org/10.1017/s0263593300010427",
    doi = "10.1017/s0263593300010427",
    openalex = "W2137082536"
}

@misc{müller1985skaracarida,
    author = "Müller, Klaus J. and Walossek, Dieter",
    title = "Skaracarida, a new order of Crustacea from the Upper Cambrian of Västergötland, Sweden",
    year = "1985",
    booktitle = "Fossils and Strata",
    url = "https://doi.org/10.18261/8200074986-1985",
    doi = "10.18261/8200074986-1985"
}

A tiny arthropod, with five growth stages, is described. Three of the instars are metanauplius‐like larvae, having unsegmented bodies and four pairs of appendages. The largest stage, with a length of about 1.5 mm, may still be immature. Its body is divided into three tagmata. The cephalon, including five appendiculate segments, h a projecting forehead with a rostral spine and a small shield with a joint between fourth and fifth segments. Eyes are absent. The trunk is composed of seven annular segments, the anterior two with appendages. The caudal end is a long pleotelson‐like segment with the anus on its ventral surface. There are seven pairs of appendages: uniramous antennulae, composed of few tubular podomeres; four pairs of biramous postantennular, almost homeomorphic cephalic appendages; two pairs on the trunk, the anterior pair being similar to the cephalic appendages except for the exopodite, the posterior being much smaller, uniramous and apparently rudimentary. Martinssonia was probably benthic, feeding on detritic particles which it stirred up from the bottom. Besides various crustacean‐like features, the new form reveals structures different from Crustacea as well as from all other known arthropodan groups. Martinssonia presumably is a descendant of an euarthropodan group, originating from the crustacean branch long before reaching the eucrustacean level of evolution.

@article{doi101111j146364091986tb00211x,
    author = "Müller, Klaus J. and Waloßek, Dieter",
    title = "Martinssonia elongata gen. et sp.n., a crustacean‐like euarthropod from the Upper Cambrian ‘Orsten’ of Sweden",
    year = "1986",
    journal = "Zoologica Scripta",
    abstract = "A tiny arthropod, with five growth stages, is described. Three of the instars are metanauplius‐like larvae, having unsegmented bodies and four pairs of appendages. The largest stage, with a length of about 1.5 mm, may still be immature. Its body is divided into three tagmata. The cephalon, including five appendiculate segments, h a projecting forehead with a rostral spine and a small shield with a joint between fourth and fifth segments. Eyes are absent. The trunk is composed of seven annular segments, the anterior two with appendages. The caudal end is a long pleotelson‐like segment with the anus on its ventral surface. There are seven pairs of appendages: uniramous antennulae, composed of few tubular podomeres; four pairs of biramous postantennular, almost homeomorphic cephalic appendages; two pairs on the trunk, the anterior pair being similar to the cephalic appendages except for the exopodite, the posterior being much smaller, uniramous and apparently rudimentary. Martinssonia was probably benthic, feeding on detritic particles which it stirred up from the bottom. Besides various crustacean‐like features, the new form reveals structures different from Crustacea as well as from all other known arthropodan groups. Martinssonia presumably is a descendant of an euarthropodan group, originating from the crustacean branch long before reaching the eucrustacean level of evolution.",
    url = "https://doi.org/10.1111/j.1463-6409.1986.tb00211.x",
    doi = "10.1111/j.1463-6409.1986.tb00211.x",
    openalex = "W2015242089"
}

The morphology and early ontogeny of Agnostus pisiformis (Linnaeus 1757) is described on the basis of more than a hundred phosphatized, mostly enrolled specimens, etched from nodular limestones of the Upper Cambrian Agnostus pisiformis Zone, Västergötland, Sweden. Gradual, anameric development. with only slight morphological change suggests that most of the recognized structures can be generalized also for later developmental stages up to the adult. The tergal components, cephalic and pygidial shields and two pleurotergites, form a highly symmetrical test, with all rims fitting tightly together when clasped together edge to edge. Complete enclosure of the test may have protected the soft ventral side, while Agnostus swam actively when the two shields were slightly gaping. Locomotion was effected by the strong exopodites of the second and third cephalic appendages. Most probably the environment in which A. pisiformis lived was a flocculent zone at the bottom of the Alum Sea, where the animals swam or floated around, as is also suggested for the other orsten arthropods. Various morphological details of agnostids are simply plesiomorphic, i.e. retained from the groundplan of the Arachnata. Those features which point to affinitites with the polymerid trilobites are most clearly in the exoskeleton and in the ontogeny. The numerous modifications of the morphology of A. pisiformis from the general polymerid trilobite body plan and features hitherto unknown from trilobites and even other arthropods confirm the separate rank of the Agnostina within the Trilobita.

@book{doi101826182000751171987,
    author = "Müller, Klaus J. and Waloßek, Dieter",
    title = "Morphology, ontogeny, and life habit of Agnostus pisiformis from the Upper Cambrian of Sweden",
    year = "1987",
    booktitle = "Fossils and strata",
    abstract = "The morphology and early ontogeny of Agnostus pisiformis (Linnaeus 1757) is described on the basis of more than a hundred phosphatized, mostly enrolled specimens, etched from nodular limestones of the Upper Cambrian Agnostus pisiformis Zone, Västergötland, Sweden. Gradual, anameric development. with only slight morphological change suggests that most of the recognized structures can be generalized also for later developmental stages up to the adult. The tergal components, cephalic and pygidial shields and two pleurotergites, form a highly symmetrical test, with all rims fitting tightly together when clasped together edge to edge. Complete enclosure of the test may have protected the soft ventral side, while Agnostus swam actively when the two shields were slightly gaping. Locomotion was effected by the strong exopodites of the second and third cephalic appendages. Most probably the environment in which A. pisiformis lived was a flocculent zone at the bottom of the Alum Sea, where the animals swam or floated around, as is also suggested for the other orsten arthropods. Various morphological details of agnostids are simply plesiomorphic, i.e. retained from the groundplan of the Arachnata. Those features which point to affinitites with the polymerid trilobites are most clearly in the exoskeleton and in the ontogeny. The numerous modifications of the morphology of A. pisiformis from the general polymerid trilobite body plan and features hitherto unknown from trilobites and even other arthropods confirm the separate rank of the Agnostina within the Trilobita.",
    url = "https://doi.org/10.18261/8200075117-1987",
    doi = "10.18261/8200075117-1987",
    openalex = "W109776588",
    references = "doi101017s0263593300003217, doi101017s0263593300010452, doi101098rstb19850139, doi101111j150239311972tb00843x, doi101127zdgg1111959434, doi10182618200049639197506, doi10182618200093301197301, doi105281zenodo15992748, müller1983crustacea, openalexw2413383410, openalexw2612667057"
}

Search for new material yielded more than ninety specimens of different growth stages of Bredocaris admirabilis Müller, 1983. It enables us now to present an extended description of the largest stage, considered as adult, and of the larval sequence. Discovery of the tagma boundary of the cephalon behind the fifth pair of appendages led to the identification of the second maxilla, which has the same design as the thoracopods and is incorporated within the trunk limb series. The larval sequence comprises five successive metanaupliar instars, with delay of development of post-maxillulary limbs. Stages between larvae and the presumed adult have not been found. Bredocaris, about 0.85 mm long as adult, is assumed to have lived epibenthically, swimming closely above a flocculent bottom layer. Lack of special feeding structures on the trunk limbs and retention of the larval cephalic feeding apparatus in the adult suggest rather simple nutritory habits; filter feeding can be ruled out. The morphology, in particular the possession of seven pairs of thoracopods, and ontogeny indicate a systematic position of Bredocaris within the Maxillopoda and close alliance to the shield-bearing members of this subclass, the Thecostraca. Differences between Bredocaris and all known maxillopodan taxa is the basis for proposing the new order Orstenocarida and new family Bredocarididae. The major diagnostic characters of this new order include: a simple, posteriorly indented head shield, probably compound eyes, anterior three head appendages of naupliar shape, a 1st maxilla with rudimentary exopod and specialized for trophic function, a 2nd maxilla of trunklimb shape, a thorax composed of seven segments, each with a pair of biramous paddle-shaped thoracopods, and a uniform abdomen carrying inarticulate, unsegmented furcal rami.

@incollection{doi10182618200374122198801,
    author = "Müller, Klaus J. and Waloßek, Dieter",
    title = "External morphology and larval development of the Upper Cambrian maxillopod Bredocaris admirabilis",
    year = "1988",
    booktitle = "Fossils and strata",
    abstract = "Search for new material yielded more than ninety specimens of different growth stages of Bredocaris admirabilis Müller, 1983. It enables us now to present an extended description of the largest stage, considered as adult, and of the larval sequence. Discovery of the tagma boundary of the cephalon behind the fifth pair of appendages led to the identification of the second maxilla, which has the same design as the thoracopods and is incorporated within the trunk limb series. The larval sequence comprises five successive metanaupliar instars, with delay of development of post-maxillulary limbs. Stages between larvae and the presumed adult have not been found. Bredocaris, about 0.85 mm long as adult, is assumed to have lived epibenthically, swimming closely above a flocculent bottom layer. Lack of special feeding structures on the trunk limbs and retention of the larval cephalic feeding apparatus in the adult suggest rather simple nutritory habits; filter feeding can be ruled out. The morphology, in particular the possession of seven pairs of thoracopods, and ontogeny indicate a systematic position of Bredocaris within the Maxillopoda and close alliance to the shield-bearing members of this subclass, the Thecostraca. Differences between Bredocaris and all known maxillopodan taxa is the basis for proposing the new order Orstenocarida and new family Bredocarididae. The major diagnostic characters of this new order include: a simple, posteriorly indented head shield, probably compound eyes, anterior three head appendages of naupliar shape, a 1st maxilla with rudimentary exopod and specialized for trophic function, a 2nd maxilla of trunklimb shape, a thorax composed of seven segments, each with a pair of biramous paddle-shaped thoracopods, and a uniform abdomen carrying inarticulate, unsegmented furcal rami.",
    url = "https://doi.org/10.18261/8200374122-1988-01",
    doi = "10.18261/8200374122-1988-01",
    openalex = "W4385629156"
}

Walossek, D. & Muller, K. J. 1990 10 15: Upper Cambrian stem-lineage crustaceans and their bearing upon the monophyletic origin of Crustacea and the position of Agnostus. Lethaia, Vol. 23, pp. 409–427. Oslo. ISSN 0024–1164. Three new arthropods in uncompressed condition have been discovered in Upper Cambrian limestone nodules (Orsten) of Vastergotland, Sweden. Together with Martinssonia elongafa Muller & Walossek, 1986, they are recognized as descendants of early offshoots from the stem-lineage of Crustacea. Their morphology provides new insights into the evolutionary path and progressive development of ground plan characteristics along the stem-lineage and gives further support for the monophyletic origin of Crustacea s. str., which embraces all taxa with extant derivatives. Structures of the ventral morphology shared between these stem-lineage crustaceans and Agnostus lead to the consideration of alternatives for the currently assumed position of agnostids. ▭Crustacea. ontogeny, phosphatization. phylogeny, stem-lineage, Sweden, 3 D-preseroation, Trilobita

@article{doi101111j150239311990tb01373x,
    author = "Waloßek, Dieter and Müller, Klaus J.",
    title = "Upper Cambrian stem‐lineage crustaceans and their bearing upon the monophyletic origin of Crustacea and the position of Agnostus",
    year = "1990",
    journal = "Lethaia",
    abstract = "Walossek, D. \& Muller, K. J. 1990 10 15: Upper Cambrian stem-lineage crustaceans and their bearing upon the monophyletic origin of Crustacea and the position of Agnostus. Lethaia, Vol. 23, pp. 409–427. Oslo. ISSN 0024–1164. Three new arthropods in uncompressed condition have been discovered in Upper Cambrian limestone nodules (Orsten) of Vastergotland, Sweden. Together with Martinssonia elongafa Muller \& Walossek, 1986, they are recognized as descendants of early offshoots from the stem-lineage of Crustacea. Their morphology provides new insights into the evolutionary path and progressive development of ground plan characteristics along the stem-lineage and gives further support for the monophyletic origin of Crustacea s. str., which embraces all taxa with extant derivatives. Structures of the ventral morphology shared between these stem-lineage crustaceans and Agnostus lead to the consideration of alternatives for the currently assumed position of agnostids. ▭Crustacea. ontogeny, phosphatization. phylogeny, stem-lineage, Sweden, 3 D-preseroation, Trilobita",
    url = "https://doi.org/10.1111/j.1502-3931.1990.tb01373.x",
    doi = "10.1111/j.1502-3931.1990.tb01373.x",
    openalex = "W2047168061",
    references = "doi101016003101827190040x, doi101111j150239311979tb01234x, doi101111j150239311983tb01704x, doi1012019781003079354, doi101826182000751171987, doi1023071548351, doi105281zenodo16157257, müller1983crustacea, müller1985skaracarida, openalexw1497395003, openalexw1546177238"
}

Bodily preserved, secondarily phosphatized arthropods discovered in drill cores on He***l Peninsula, northern Poland, and in its vicinity date from the Upper Cambrian. Comparisons between a group of arthropods of the Upper Cambrian of Sweden recognized as stem-lineage crustaceans indicate that one of these new forms, Cambrocaris baltica n. gen. n. sp., also represents a derivative of the early phase of crustacean evolution prior to the crown-group level. The material also yielded a specimen identified as Skara minuta Müller & Walossek, 1985, hitherto known only from Västergotland, Sweden, and two limb fragments which cannot be assigned to species. □Crustacea, stem-lineage derivatives. Phosphatization, three-dimensional preservation, Upper Cambrian, Alum shales, ‘Orsten’, northern Poland.

@article{doi101111j150239311991tb01488x,
    author = "Waloßek, Dieter and Szaniawski, Hubert",
    title = "Cambrocaris baltica n. gen. n. sp., a possible stem‐lineage crustacean from the Upper Cambrian of Poland",
    year = "1991",
    journal = "Lethaia",
    abstract = "Bodily preserved, secondarily phosphatized arthropods discovered in drill cores on He***l Peninsula, northern Poland, and in its vicinity date from the Upper Cambrian. Comparisons between a group of arthropods of the Upper Cambrian of Sweden recognized as stem-lineage crustaceans indicate that one of these new forms, Cambrocaris baltica n. gen. n. sp., also represents a derivative of the early phase of crustacean evolution prior to the crown-group level. The material also yielded a specimen identified as Skara minuta Müller \& Walossek, 1985, hitherto known only from Västergotland, Sweden, and two limb fragments which cannot be assigned to species. □Crustacea, stem-lineage derivatives. Phosphatization, three-dimensional preservation, Upper Cambrian, Alum shales, ‘Orsten’, northern Poland.",
    url = "https://doi.org/10.1111/j.1502-3931.1991.tb01488.x",
    doi = "10.1111/j.1502-3931.1991.tb01488.x",
    openalex = "W2002285573",
    references = "doi101017s0263593300010427, doi101098rstb19850139, doi101111j146364091986tb00211x, doi101111j150239311979tb01234x, doi101111j150239311990tb01373x, doi101126science18040921283, doi10182618200374122198801, doi1023071485466, doi105860choice284524, müller1983crustacea, müller1985skaracarida"
}

@incollection{müller1991upper,
    author = "Müller, Klaus J. and Hinz, Ingelore",
    title = "Upper Cambrian conodonts from Sweden",
    year = "1991",
    booktitle = "Fossils and Strata",
    url = "https://doi.org/10.18261/8200374750-1991-01",
    doi = "10.18261/8200374750-1991-01",
    pages = "1-153"
}

@article{aldridge1992upper,
    author = "Aldridge, Richard J.",
    title = "Upper Cambrian Conodonts from Sweden",
    year = "1992",
    journal = "Palaeogeography, Palaeoclimatology, Palaeoecology",
    url = "https://doi.org/10.1016/0031-0182(92)90151-t",
    doi = "10.1016/0031-0182(92)90151-t",
    number = "3-4",
    pages = "345-346",
    volume = "95"
}

Abstract Exceptional three‐dimensional preservation of phosphatized Upper Cambrian arthropods of different groups from southern Sweden permits not only description of their morphology in full detail but also assumptions on functional morphology and life habits. Ontogenetic stages, in some cases in complete sequences, give additional information about habitual changes in the life cycle. Altogether this provides a wide data basis for phylogenetic considerations, particularly for the crustacean branch of the Arthropoda. Among the ‘Orsten’ fossils, a number could be recognized as representatives of crown‐group crustacean taxa, such as the Skaracarida and Bredocaris as members of each of the two different lineages of Maxillopoda, or Rehbachiella as a member of the Branchiopoda. Another set of forms shares some characters with the crowngroup crustaceans but lacks a large number of others. These fossils, identified as representatives of the stem line of Crustacea, provide a hitherto unknown data set for the interpretation of morphological and functional changes in the evolution towards the crown‐group of this taxon.

@article{doi101111j146363951992tb01096x,
    author = "Waloßek, Dieter and Müller, Klaus J.",
    title = "The ‘Alum Shale Window’—Contribution of ‘Orsten’ Arthropods to the Phylogeny of Crustacea",
    year = "1992",
    journal = "Acta Zoologica",
    abstract = "Abstract Exceptional three‐dimensional preservation of phosphatized Upper Cambrian arthropods of different groups from southern Sweden permits not only description of their morphology in full detail but also assumptions on functional morphology and life habits. Ontogenetic stages, in some cases in complete sequences, give additional information about habitual changes in the life cycle. Altogether this provides a wide data basis for phylogenetic considerations, particularly for the crustacean branch of the Arthropoda. Among the ‘Orsten’ fossils, a number could be recognized as representatives of crown‐group crustacean taxa, such as the Skaracarida and Bredocaris as members of each of the two different lineages of Maxillopoda, or Rehbachiella as a member of the Branchiopoda. Another set of forms shares some characters with the crowngroup crustaceans but lacks a large number of others. These fossils, identified as representatives of the stem line of Crustacea, provide a hitherto unknown data set for the interpretation of morphological and functional changes in the evolution towards the crown‐group of this taxon.",
    url = "https://doi.org/10.1111/j.1463-6395.1992.tb01096.x",
    doi = "10.1111/j.1463-6395.1992.tb01096.x",
    openalex = "W2128356442"
}

@article{vandenboogaard1992upper,
    author = "van den Boogaard, M.",
    title = "Upper cambrian conodonts from Sweden",
    year = "1992",
    journal = "Earth-Science Reviews",
    url = "https://doi.org/10.1016/0012-8252(92)90037-t",
    doi = "10.1016/0012-8252(92)90037-t",
    number = "3",
    pages = "203-204",
    volume = "32"
}

More than 130 specimens representing various growth stages of Rehbachiella kinnekullensis Müller, 1983, have permitted a detailed description of its ontogeny. It begins with a nauplius already able to swim and feed actively. The 30th stage is about 1.7 mm long, but still immature. Because the type specimens belong to earlier instars, the original diagnosis of Müller (1983) is emended. Details of the limb apparatus of late instars suggest that the animals were able to filter-feed by this stage, possibly while swimming close to the bottom. Two larval series are distin-guished by size and morphology in their early stages, but their structural differences become almost balanced subsequently. This is interpreted as intraspecific differentiation rather than as existence of two species. The entire postnaupliar feeding apparatus of Branchiopoda, which is basically adapted to filtration, is recognized here as an apomorphic character of this group. Branchiopoda comprise the two monophyletic units Anostraca and Phyllopoda (Calmanostraca, with Notostraca and Kazacharthra, and Onychura). Rehbachiella shares all major aspects of the branchiopod filter apparatus, which led to identify it as an ancestral marine branchiopod. Moreover, there are indications that Rehbachiella is a representative of the anostracan lineage, i.e. a representative of the stem-group of Sarsostraca, which include the Devonian Lipostraca and the extant Euanostraca. The long larval sequence of Rehbachiella and selective external features, induding the locomotory and feeding apparatus, are evaluated for their bearing upon the phylogeny of Branchiopoda and Crustacea in general. This study on Rehbachiella supports the monophyly of the crown-group Crustacea (sensu Walossek & Müller 1990). It also has revealed that only the first maxilla was morphologically and functionally included into the crustacean head, while subsequent limbs were addted to the head in a stepwise manner and became modified separately within the different crustacean lineages, which is of great relevance when evaluating the relationships between these.

@incollection{doi10182618200374874199301,
    author = "Waloßek, Dieter",
    title = "The Upper Cambrian Rehbachiella and the phylogeny of Branchiopoda and Crustacea",
    year = "1993",
    booktitle = "Fossils and strata",
    abstract = "More than 130 specimens representing various growth stages of Rehbachiella kinnekullensis Müller, 1983, have permitted a detailed description of its ontogeny. It begins with a nauplius already able to swim and feed actively. The 30th stage is about 1.7 mm long, but still immature. Because the type specimens belong to earlier instars, the original diagnosis of Müller (1983) is emended. Details of the limb apparatus of late instars suggest that the animals were able to filter-feed by this stage, possibly while swimming close to the bottom. Two larval series are distin-guished by size and morphology in their early stages, but their structural differences become almost balanced subsequently. This is interpreted as intraspecific differentiation rather than as existence of two species. The entire postnaupliar feeding apparatus of Branchiopoda, which is basically adapted to filtration, is recognized here as an apomorphic character of this group. Branchiopoda comprise the two monophyletic units Anostraca and Phyllopoda (Calmanostraca, with Notostraca and Kazacharthra, and Onychura). Rehbachiella shares all major aspects of the branchiopod filter apparatus, which led to identify it as an ancestral marine branchiopod. Moreover, there are indications that Rehbachiella is a representative of the anostracan lineage, i.e. a representative of the stem-group of Sarsostraca, which include the Devonian Lipostraca and the extant Euanostraca. The long larval sequence of Rehbachiella and selective external features, induding the locomotory and feeding apparatus, are evaluated for their bearing upon the phylogeny of Branchiopoda and Crustacea in general. This study on Rehbachiella supports the monophyly of the crown-group Crustacea (sensu Walossek \& Müller 1990). It also has revealed that only the first maxilla was morphologically and functionally included into the crustacean head, while subsequent limbs were addted to the head in a stepwise manner and became modified separately within the different crustacean lineages, which is of great relevance when evaluating the relationships between these.",
    url = "https://doi.org/10.18261/8200374874-1993-01",
    doi = "10.18261/8200374874-1993-01",
    openalex = "W4385643402",
    references = "doi1010160012825280900641, doi1010160305197885900559, doi101038086174a0, doi101098rstb19680017, doi101098rstb19850139, doi101111j150239311979tb01234x, doi101111j150239311990tb01373x, doi101111j150239311991tb01488x, doi101126science2464928339, doi101146annureves10110179001551, doi10182618200049639197506, doi104095103458, doi105281zenodo15992748, doi105860choice264482, doi105962bhlpart4119, dzik1988the, morris1979the, müller1983crustacea, openalexw2240758963, openalexw2297370949, openalexw2747754219, openalexw353142951, openalexw601774539, ulrich1931cambrian"
}

Lithostratigraphy and depositional and epeirogenic history of the upper Placentian Series (Cuslett-Fosters Point Formations of the Bonavista Group) and Branchian Series (Brigus Formation) are identical in the northern Antigonish Highlands; Cape Breton Island; and eastern Placentia Bay, southeastern Newfoundland. Preliminary evidence suggests that the lower Middle Cambrian is present in the field area. A unified, uppermost Precambrian–Lower Cambrian, formation- and member-level nomenclature is appropriate to Avalonian North America, and the stratigraphic nomenclature of southeastern Newfoundland is applied in northern mainland Nova Scotia. Latest Placentian shoaling and deposition of a peritidal carbonate lithosome and unconformable onlap of the trilobite-bearing Branchian Series occurred in shallow Avalonian shale basins from eastern Massachusetts to central England. Uppermost Placentian Series faunas are very diverse in the Fosters Point Formation. Limited similarities with the South Australian Lower Cambrian are indicated by the presence of Camenella sp. cf. C. reticulosa, Conotheca australiensis, and Hyptiotheca sp., but these forms do not contribute to highly resolved correlation. Twenty-eight taxa are illustrated from the upper Placentian and Branchian Series. Caveacus rectus n. gen. and sp., a phosphatic problematicum, is limited to the upper Placentian Series. The oldest, skeletalized, macrophagous predators are the Pseudoconodontida and the later appearing Protoconodontida (n. orders). The Pseudoconodontida includes the Protohertzinacea n. superfamily and Strictocorniculacea n. superfamily (with the Rhombocorniculidae and Strictocorniculidae n. families). Strictocorniculum vanallerum n. gen. and sp. is described. The tommotiid family Sunnaginiidae emend. includes Eccentrotheca, Sunnaginia, Kulparina, and Jayceia deltiformis n. gen. and sp.

@article{doi101017s0022336000034879,
    author = "Landing, Ed",
    title = "Upper Placentian—Branchian series of mainland Nova Scotia (middle-upper Lower Cambrian): Faunas, paleoenvironments, and stratigraphic revision",
    year = "1995",
    journal = "Journal of Paleontology",
    abstract = "Lithostratigraphy and depositional and epeirogenic history of the upper Placentian Series (Cuslett-Fosters Point Formations of the Bonavista Group) and Branchian Series (Brigus Formation) are identical in the northern Antigonish Highlands; Cape Breton Island; and eastern Placentia Bay, southeastern Newfoundland. Preliminary evidence suggests that the lower Middle Cambrian is present in the field area. A unified, uppermost Precambrian–Lower Cambrian, formation- and member-level nomenclature is appropriate to Avalonian North America, and the stratigraphic nomenclature of southeastern Newfoundland is applied in northern mainland Nova Scotia. Latest Placentian shoaling and deposition of a peritidal carbonate lithosome and unconformable onlap of the trilobite-bearing Branchian Series occurred in shallow Avalonian shale basins from eastern Massachusetts to central England. Uppermost Placentian Series faunas are very diverse in the Fosters Point Formation. Limited similarities with the South Australian Lower Cambrian are indicated by the presence of Camenella sp. cf. C. reticulosa, Conotheca australiensis, and Hyptiotheca sp., but these forms do not contribute to highly resolved correlation. Twenty-eight taxa are illustrated from the upper Placentian and Branchian Series. Caveacus rectus n. gen. and sp., a phosphatic problematicum, is limited to the upper Placentian Series. The oldest, skeletalized, macrophagous predators are the Pseudoconodontida and the later appearing Protoconodontida (n. orders). The Pseudoconodontida includes the Protohertzinacea n. superfamily and Strictocorniculacea n. superfamily (with the Rhombocorniculidae and Strictocorniculidae n. families). Strictocorniculum vanallerum n. gen. and sp. is described. The tommotiid family Sunnaginiidae emend. includes Eccentrotheca, Sunnaginia, Kulparina, and Jayceia deltiformis n. gen. and sp.",
    url = "https://doi.org/10.1017/s0022336000034879",
    doi = "10.1017/s0022336000034879",
    openalex = "W2487555070",
    references = "aldridge1992upper, doi1010160012825272900724, doi101017s0022336000018965, doi101017s0022336000036465, doi1011300091761319880160452ibolim23co2, doi1011300091761319940220179pcbgsr23co2, doi101130spe196, doi101826182003741571989, doi1023071483846, openalexw1540907293, openalexw587905045, vandenboogaard1992upper"
}

Although the biology of the reptantian Decapoda has been much studied, the last comprehensive review of reptantian systematics was published more than 80 years ago. We have used cladistic methods to reconstruct the phylogenetic system of the reptantian Decapoda. We can show that the Reptantia represent a monophyletic taxon. The classical groups, the ‘Palinura’, ‘Astacura’ and ‘Anomura’ are paraphyletic assemblages. The Polychelida is the sister-group of all other reptantians. The Astacida is not closely related to the Homarida, but is part of a large monophyletic taxon which also includes the Thalassinida, Anomala and Brachyura. The Anomala and Brachyura are sister-groups and the Thalassinida is the sister-group of both of them. Based on our reconstruction of the sister-group relationships within the Reptantia, we discuss alternative hypotheses of reptantian interrelationships, the systematic position of the Reptantia within the decapods, and draw some conclusions concerning the habits and appearance of the reptantian stem species.

@article{doi101111j109636421995tb00936x,
    author = "Scholtz, Gerhard and Richter, Stefan",
    title = "Phylogenetic systematics of the reptantian Decapoda (Crustacea, Malacostraca)",
    year = "1995",
    journal = "Zoological Journal of the Linnean Society",
    abstract = "Although the biology of the reptantian Decapoda has been much studied, the last comprehensive review of reptantian systematics was published more than 80 years ago. We have used cladistic methods to reconstruct the phylogenetic system of the reptantian Decapoda. We can show that the Reptantia represent a monophyletic taxon. The classical groups, the ‘Palinura’, ‘Astacura’ and ‘Anomura’ are paraphyletic assemblages. The Polychelida is the sister-group of all other reptantians. The Astacida is not closely related to the Homarida, but is part of a large monophyletic taxon which also includes the Thalassinida, Anomala and Brachyura. The Anomala and Brachyura are sister-groups and the Thalassinida is the sister-group of both of them. Based on our reconstruction of the sister-group relationships within the Reptantia, we discuss alternative hypotheses of reptantian interrelationships, the systematic position of the Reptantia within the decapods, and draw some conclusions concerning the habits and appearance of the reptantian stem species.",
    url = "https://doi.org/10.1111/j.1096-3642.1995.tb00936.x",
    doi = "10.1111/j.1096-3642.1995.tb00936.x",
    openalex = "W2126428088",
    references = "doi101038150474a0, doi1023071548154, doi1023073700, openalexw566092230"
}

Trying to review the Cambrian diversity of Crustacea, it became necessary to first characterize the Crustacea as a monophylum with a reconstruction of the ground pattern and autapomorphies of its stem species. Some of the major evolutionary developments toward the crown group, Eucrustacea, are also illuminated. The view presented is founded largely on minute three-dimensional, phosphatized fossils from the Swedish ‘Orsten’, a special type of bituminous Cambrian limestone rock, which have been studied since about 15 years now in co-operation with the discoverer of the ‘Orsten’ material, Klaus Müller from Bonn. With respect to the lowermost Cambrian record of the Phosphatocopina, the possible sister group of Eucrustacea and most abundant in the ‘Orsten’ material, it seems evident that Crustacea must have developed well before the Cambrian and had diversified into all major descendent lines before the end of this time period. The missing record, particularly of the Malacostraca (those records noted so far can be clearly falsified) is interpreted as simply due to the small preservational window we have into the Cambrian world so far. In fact, there are only two major sources: the flat fossils in the millimetre to centimetre range from Lower to Upper Middle Cambrian Burgess Shale type of localities, and the minute 3D-preserved fossils from Lower to Upper Cambrian ‘Orsten’ localities. The evident origin of the Crustacea well down in the Pre-Cambrian is, in my view, a further challenge to the idea of a “Cambrian explosion”.

@incollection{doi1011639789004630543003,
    author = "Waloßek, Dieter",
    title = "On the Cambrian Diversity of Crustacea",
    year = "1999",
    abstract = "Trying to review the Cambrian diversity of Crustacea, it became necessary to first characterize the Crustacea as a monophylum with a reconstruction of the ground pattern and autapomorphies of its stem species. Some of the major evolutionary developments toward the crown group, Eucrustacea, are also illuminated. The view presented is founded largely on minute three-dimensional, phosphatized fossils from the Swedish ‘Orsten’, a special type of bituminous Cambrian limestone rock, which have been studied since about 15 years now in co-operation with the discoverer of the ‘Orsten’ material, Klaus Müller from Bonn. With respect to the lowermost Cambrian record of the Phosphatocopina, the possible sister group of Eucrustacea and most abundant in the ‘Orsten’ material, it seems evident that Crustacea must have developed well before the Cambrian and had diversified into all major descendent lines before the end of this time period. The missing record, particularly of the Malacostraca (those records noted so far can be clearly falsified) is interpreted as simply due to the small preservational window we have into the Cambrian world so far. In fact, there are only two major sources: the flat fossils in the millimetre to centimetre range from Lower to Upper Middle Cambrian Burgess Shale type of localities, and the minute 3D-preserved fossils from Lower to Upper Cambrian ‘Orsten’ localities. The evident origin of the Crustacea well down in the Pre-Cambrian is, in my view, a further challenge to the idea of a “Cambrian explosion”.",
    url = "https://doi.org/10.1163/9789004630543\_003",
    doi = "10.1163/9789004630543\_003",
    openalex = "W4383481311"
}

Among a set of small, secondarily phosphatised larval arthropods from the Upper Cambrian ‘Orsten’ of Sweden, described by Müller and Walossek in 1986, one form bears a remarkable resemblance to the hatching protonymph larva of extant Pantopoda. This ‘larva D’ shares with protonymphs their gross body form, the anteroventral mouth on a slightly off‐set forehead region, the cheliceral morphology, two homeomorphic pairs of post‐cheliceral limbs, and further detailed similarities. It is described herein as Cambropycnogon klausmuelleri gen. et sp. nov. and is proposed as the oldest unequivocal record of both Pycnogonida and Chelicerata. Plesiomorphic features such as a pair of rudimentary pre‐cheliceral limbs and the gnathobasic basipods of the two post‐cheliceral limbs distinguish it from all known larvae of extant Pantopoda and lead us to propose a phylogeny of the Pycnogonida of the form (Cambropycnogon klausmuelleri + (Palaeoisopus + (Palaeopantopus + Pantopoda))). The fossil may help to resolve the long debate about the relationships of Pycnogonida to other Arthropoda and supports a (Pycnogonida + Euchelicerata) relationship within the Chelicerata. The pre‐cheliceral limbs in this fossil support traditional morphological studies in which the chelicera represent the second (a2) head appendage, corresponding to the crustacean ‘second antennae’, and contradict recent data based on homeobox genes implying that the chelicerae are the first (a1) head appendages homologous with crustacean first antennae.

@article{doi1011111475498300244,
    author = "Waloszek, Dieter and Dunlop, Jason A.",
    title = "A Larval Sea Spider (Arthropoda: Pycnogonida) from the Upper Cambrian ‘orsten’ of Sweden, and the Phylogenetic Position of Pycnogonids",
    year = "2002",
    journal = "Palaeontology",
    abstract = "Among a set of small, secondarily phosphatised larval arthropods from the Upper Cambrian ‘Orsten’ of Sweden, described by Müller and Walossek in 1986, one form bears a remarkable resemblance to the hatching protonymph larva of extant Pantopoda. This ‘larva D’ shares with protonymphs their gross body form, the anteroventral mouth on a slightly off‐set forehead region, the cheliceral morphology, two homeomorphic pairs of post‐cheliceral limbs, and further detailed similarities. It is described herein as Cambropycnogon klausmuelleri gen. et sp. nov. and is proposed as the oldest unequivocal record of both Pycnogonida and Chelicerata. Plesiomorphic features such as a pair of rudimentary pre‐cheliceral limbs and the gnathobasic basipods of the two post‐cheliceral limbs distinguish it from all known larvae of extant Pantopoda and lead us to propose a phylogeny of the Pycnogonida of the form (Cambropycnogon klausmuelleri + (Palaeoisopus + (Palaeopantopus + Pantopoda))). The fossil may help to resolve the long debate about the relationships of Pycnogonida to other Arthropoda and supports a (Pycnogonida + Euchelicerata) relationship within the Chelicerata. The pre‐cheliceral limbs in this fossil support traditional morphological studies in which the chelicera represent the second (a2) head appendage, corresponding to the crustacean ‘second antennae’, and contradict recent data based on homeobox genes implying that the chelicerae are the first (a1) head appendages homologous with crustacean first antennae.",
    url = "https://doi.org/10.1111/1475-4983.00244",
    doi = "10.1111/1475-4983.00244",
    openalex = "W2003658167",
    references = "doi101098rstb19850139"
}

Limestone beds intercalated within a succession of sandstones, siltstones, and shales of the subsurface Deadwood Formation, cored in two wells in Alberta and Saskatchewan, yielded twelve species assigned to eight genera of organophosphatic brachiopods (Subphylum Linguliformea). The nine species recovered from the Alberta well are Marjuman (late Middle to early Late Cambrian) in age. Three of these species, Neotreta davidi Popov, Berg-Madsen, and Holmer, 1994; Picnotreta debilis Henderson and MacKinnon, 1981; and Stilpnotreta magna Henderson and MacKinnon, 1981, are associated with the Mindyallan (early Late Cambrian) of Queensland, and are previously unknown from Laurentia. This brachiopod fauna occurs with a diverse fauna of paraconodont species. The Saskatchewan well yielded three species of Linnarssonella, belonging to the upper Steptoean to the lower Sunwaptan (middle Late Cambrian). One new subfamily, Neotretinae, is erected, and two new species, Rhondellina albertensis, and Linnarssonella tubicula are described. Linnarssonella elongata Bell, 1941, is reinstated as a valid species. This fauna occurs with a diverse fauna of paraconodont species and is overlain, 226 feet higher, by conodonts of the Early Sunwaptan Proconodontus Zone.

@article{doi101017s0022336000043602,
    author = "Robson, Sean P. and Nowlan, Godfrey S. and Pratt, Brian R.",
    title = "Middle to Upper Cambrian linguliformean brachiopods from the Deadwood Formation of subsurface Alberta and Saskatchewan, Canada",
    year = "2003",
    journal = "Journal of Paleontology",
    abstract = "Limestone beds intercalated within a succession of sandstones, siltstones, and shales of the subsurface Deadwood Formation, cored in two wells in Alberta and Saskatchewan, yielded twelve species assigned to eight genera of organophosphatic brachiopods (Subphylum Linguliformea). The nine species recovered from the Alberta well are Marjuman (late Middle to early Late Cambrian) in age. Three of these species, Neotreta davidi Popov, Berg-Madsen, and Holmer, 1994; Picnotreta debilis Henderson and MacKinnon, 1981; and Stilpnotreta magna Henderson and MacKinnon, 1981, are associated with the Mindyallan (early Late Cambrian) of Queensland, and are previously unknown from Laurentia. This brachiopod fauna occurs with a diverse fauna of paraconodont species. The Saskatchewan well yielded three species of Linnarssonella, belonging to the upper Steptoean to the lower Sunwaptan (middle Late Cambrian). One new subfamily, Neotretinae, is erected, and two new species, Rhondellina albertensis, and Linnarssonella tubicula are described. Linnarssonella elongata Bell, 1941, is reinstated as a valid species. This fauna occurs with a diverse fauna of paraconodont species and is overlain, 226 feet higher, by conodonts of the Early Sunwaptan Proconodontus Zone.",
    url = "https://doi.org/10.1017/s0022336000043602",
    doi = "10.1017/s0022336000043602",
    openalex = "W4256204955",
    references = "aldridge1992upper, doi101017cbo9781139104036004, doi101017s0016756800013029, doi101098rstb19960101, doi101127zdgg1111959434, doi101130spe196p43, doi101139e97098, doi1018814epiiugs2000v23i3006, openalexw2101732591, openalexw2207565996, openalexw2613036873"
}

The Upper Cambrian faunas of Scandinavia are generally dominated by olenid trilobites, which provide a firm basis for the biostratigraphic classification. The olenids tend, however, to be provincial and facies controlled. By contrast, many agnostoid genera and species have a nearly worldwide distribution and are excellent biostratigraphic indices in Middle and Upper Cambrian strata. Three distinctive and geographically widely distributed agnostoid species are known from the lower part of the Upper Cambrian in Scandinavia: Linguagnostus reconditus POLETAEVA and ROMANENKO, 1970, Aspidagnostus lunulosus (KRYSKOV in Borovikov and Kryskov, 1963), and Glyptagnostus reticulatus (ANGELIN, 1851). They are the most valuable species available for correlations with Upper Cambrian deposits outside Baltica. L. reconditus is seemingly confined to the Agnostus pisiformis Zone and provides strong evidence for correlation of that zone with the recently defined L. reconditus Zone of Peng and Robison. G. reticulatus appears in the Olenus gibbosus Subzone and ranges up into the O. wahlenbergi Subzone, suggesting that the lower part of the Olenus/Agnostus (Homagnostus) obesus Zone correlates with the G. reticulatus Zone in, e.g., Australia, China, and Kazakhstan. The presence of A. lunulosus in the O. gibbosus Subzone provides additional evidence for this correlation. Higher in the sequence agnostoids become rare, and the species recorded from the medial and upper Upper Cambrian of Baltica permit only broad correlations with other continents.

@article{doi101344105000001599,
    author = "Ahlberg, Per",
    title = "Trilobites and intercontinental tie points in the Upper Cambrian of Scandinavia",
    year = "2003",
    journal = "Geologica Acta",
    abstract = "The Upper Cambrian faunas of Scandinavia are generally dominated by olenid trilobites, which provide a firm basis for the biostratigraphic classification. The olenids tend, however, to be provincial and facies controlled. By contrast, many agnostoid genera and species have a nearly worldwide distribution and are excellent biostratigraphic indices in Middle and Upper Cambrian strata. Three distinctive and geographically widely distributed agnostoid species are known from the lower part of the Upper Cambrian in Scandinavia: Linguagnostus reconditus POLETAEVA and ROMANENKO, 1970, Aspidagnostus lunulosus (KRYSKOV in Borovikov and Kryskov, 1963), and Glyptagnostus reticulatus (ANGELIN, 1851). They are the most valuable species available for correlations with Upper Cambrian deposits outside Baltica. L. reconditus is seemingly confined to the Agnostus pisiformis Zone and provides strong evidence for correlation of that zone with the recently defined L. reconditus Zone of Peng and Robison. G. reticulatus appears in the Olenus gibbosus Subzone and ranges up into the O. wahlenbergi Subzone, suggesting that the lower part of the Olenus/Agnostus (Homagnostus) obesus Zone correlates with the G. reticulatus Zone in, e.g., Australia, China, and Kazakhstan. The presence of A. lunulosus in the O. gibbosus Subzone provides additional evidence for this correlation. Higher in the sequence agnostoids become rare, and the species recorded from the medial and upper Upper Cambrian of Baltica permit only broad correlations with other continents.",
    url = "https://doi.org/10.1344/105.000001599",
    doi = "10.1344/105.000001599",
    openalex = "W2169703225",
    references = "doi101017s0263593300002133"
}

‘Orsten’-type preservation, i. e., phosphatisation of cuticles without further diagenetic deformation, has yielded three-dimensional fossils at a scale of 0.1–2.0 mm. Such fossils, first described from Upper Cambrian limestone nodules found in Sweden, have been reported from several continents and from the early Cambrian (approx. 520 M. y. BP) to the early Cretaceous (approx. 100 M. y. BP). Fossils from Cambrian ‘Orsten’-type lagerstatten are mainly representatives of different euarthropod groups and also of different evolutionary levels. This allowed the reconstruction of the early phylogeny particularly of Crustacea in great detail and the recovery of major evolutionary traits within this group, i. e., in the progressive modification of the locomotory and feeding apparatus of the head region. More recently, derivatives also of the early stem lineage toward the Euarthropoda have been discovered. These include apparently parasitic larvae of stemlineage Pentastomida (tongue worms) today living in various tetrapods, a minute fossil related to the equally minute tardigrades (water bears), and fragments of a small tubular organism with segmental tubular limbs, interpreted as the first lobopodian in an ‘Orsten’-type preservation. Lobopodians are worm-like derivatives of the earliest phase in the evolution of arthropods before the development of a sclerotic, segmented dorsal cuticle (arthrodized tergum) and similarly segmented limbs (arthropodia), hitherto known only from the Lower to Middle Cambrian. The presence of these “pre-euarthropods,” which lack, or partly lack, characteristic features developed later in the arthropod evolutionary lineage, and the recent record of phosphatocopine Crustacea in the earliest Palaeozoic are regarded as a support for the view that the ancestry of Arthropoda lies much further back, possibly well in the late Pre-Cambrian. This does not support a “Cambrian explosion”.

@article{doi102517prpsj771,
    author = "Waloszek, Dieter",
    title = "The ‘Orsten’ window — a three-dimensionally preserved Upper Cambrian meiofauna and its contribution to our understanding of the evolution of Arthropoda",
    year = "2003",
    journal = "Paleontological Research",
    abstract = "‘Orsten’-type preservation, i. e., phosphatisation of cuticles without further diagenetic deformation, has yielded three-dimensional fossils at a scale of 0.1–2.0 mm. Such fossils, first described from Upper Cambrian limestone nodules found in Sweden, have been reported from several continents and from the early Cambrian (approx. 520 M. y. BP) to the early Cretaceous (approx. 100 M. y. BP). Fossils from Cambrian ‘Orsten’-type lagerstatten are mainly representatives of different euarthropod groups and also of different evolutionary levels. This allowed the reconstruction of the early phylogeny particularly of Crustacea in great detail and the recovery of major evolutionary traits within this group, i. e., in the progressive modification of the locomotory and feeding apparatus of the head region. More recently, derivatives also of the early stem lineage toward the Euarthropoda have been discovered. These include apparently parasitic larvae of stemlineage Pentastomida (tongue worms) today living in various tetrapods, a minute fossil related to the equally minute tardigrades (water bears), and fragments of a small tubular organism with segmental tubular limbs, interpreted as the first lobopodian in an ‘Orsten’-type preservation. Lobopodians are worm-like derivatives of the earliest phase in the evolution of arthropods before the development of a sclerotic, segmented dorsal cuticle (arthrodized tergum) and similarly segmented limbs (arthropodia), hitherto known only from the Lower to Middle Cambrian. The presence of these “pre-euarthropods,” which lack, or partly lack, characteristic features developed later in the arthropod evolutionary lineage, and the recent record of phosphatocopine Crustacea in the earliest Palaeozoic are regarded as a support for the view that the ancestry of Arthropoda lies much further back, possibly well in the late Pre-Cambrian. This does not support a “Cambrian explosion”.",
    url = "https://doi.org/10.2517/prpsj.7.71",
    doi = "10.2517/prpsj.7.71",
    openalex = "W1990348973",
    references = "doi101038387489a0, doi101038990080, doi1011111475498300244, doi101126science2665185637, doi1011639789004630543003, doi101826182000751171987, doi10182618200374874199301, doi101826182003769311997, müller1991upper, openalexw2134978213, vandenboogaard1992upper"
}

Löfgren, Anita (2003): Conodont faunas with Lenodus variabilis in the upper Arenigian to lower Llanvirnian of Sweden. Acta Palaeontologica Polonica 48 (3): 417-436, DOI: 10.5281/zenodo.13345912

@article{doi105281zenodo13345911,
    author = "Löfgren, Anita",
    title = "Conodont faunas with Lenodus variabilis in the upper Arenigian to lower Llanvirnian of Sweden",
    year = "2003",
    abstract = "Löfgren, Anita (2003): Conodont faunas with Lenodus variabilis in the upper Arenigian to lower Llanvirnian of Sweden. Acta Palaeontologica Polonica 48 (3): 417-436, DOI: 10.5281/zenodo.13345912",
    url = "https://doi.org/10.5281/zenodo.13345911",
    doi = "10.5281/zenodo.13345911",
    openalex = "W2041234611",
    references = "doi101826197814051698822001"
}

@incollection{maas2003morphology,
    author = "Maas, Andreas and Waloszek, Dieter and Müller, Klaus J.",
    title = {Morphology, ontogeny and phylogeny of the Phosphatocopina (Crustacea) from the Upper Cambrian "Orsten" of Sweden},
    year = "2003",
    booktitle = "Fossils and Strata",
    url = "https://doi.org/10.18261/9781405169875-2003-01",
    doi = "10.18261/9781405169875-2003-01",
    pages = "1-238"
}

Abstract Since 1985, samples with a total weight of more than 14,000 kg, mainly from three key sections in western and northwestern Hunan, South China, have been processed for conodonts. In strata older than the late Late Cambrian paraconodonts have proved useful for stratigraphic subdivision and correlation. Thirteen conodont zones are proposed in the Middle Cambrian through lowermost Ordovician. The correlation between these zones and those of North China, western U. S.A., western Newfoundland, Canada, and Iran is discussed. In ascending order, these 13 zones are as follows: The Gapparodus bisulcatus‐Westergaardodina brevidens Zone, Shandongodus priscus‐Hunanognathus tricuspidatus Zone, Westergaardodina quadrata Zone, Westergaardodina matsushitai‐W. grandidens Zone, Westergaardodina lui‐W. ani Zone, Westergaardodina cf. calix‐Prooneotodus rotundatus Zone, Proconodontus tenuiserratus Zone, Proconodontus Zone, Eoconodontus Zone, Cordylodus proavus Zone, Cordylodus intermedius Zone, Cordylodus lindstromi Zone, and Cordylodus angulatus Zone (lower part). The Westergaardodina lui‐W. ani and Westergaardodina cf. calix‐Prooneotodus rotundatus Zones replace the Westergaardodina proligula and Westergaardodina cf. behrae‐Prooneotodus rotundatus Zones, respectively, in the lowermost Upper Cambrian. Two new species (Westergaardodina lui and Westergaardodina ani) and one conditionally identified species (Westergaardodina cf. calix) are described.

@article{doi101111j175567242004tb00776x,
    author = "Xiping, DONG and Repetski, John E. and Bergström, Stig M.",
    title = "Conodont Biostratigraphy of the Middle Cambrian through Lowermost Ordovician in Hunan, South China",
    year = "2004",
    journal = "Acta Geologica Sinica - English Edition",
    abstract = "Abstract Since 1985, samples with a total weight of more than 14,000 kg, mainly from three key sections in western and northwestern Hunan, South China, have been processed for conodonts. In strata older than the late Late Cambrian paraconodonts have proved useful for stratigraphic subdivision and correlation. Thirteen conodont zones are proposed in the Middle Cambrian through lowermost Ordovician. The correlation between these zones and those of North China, western U. S.A., western Newfoundland, Canada, and Iran is discussed. In ascending order, these 13 zones are as follows: The Gapparodus bisulcatus‐Westergaardodina brevidens Zone, Shandongodus priscus‐Hunanognathus tricuspidatus Zone, Westergaardodina quadrata Zone, Westergaardodina matsushitai‐W. grandidens Zone, Westergaardodina lui‐W. ani Zone, Westergaardodina cf. calix‐Prooneotodus rotundatus Zone, Proconodontus tenuiserratus Zone, Proconodontus Zone, Eoconodontus Zone, Cordylodus proavus Zone, Cordylodus intermedius Zone, Cordylodus lindstromi Zone, and Cordylodus angulatus Zone (lower part). The Westergaardodina lui‐W. ani and Westergaardodina cf. calix‐Prooneotodus rotundatus Zones replace the Westergaardodina proligula and Westergaardodina cf. behrae‐Prooneotodus rotundatus Zones, respectively, in the lowermost Upper Cambrian. Two new species (Westergaardodina lui and Westergaardodina ani) and one conditionally identified species (Westergaardodina cf. calix) are described.",
    url = "https://doi.org/10.1111/j.1755-6724.2004.tb00776.x",
    doi = "10.1111/j.1755-6724.2004.tb00776.x",
    openalex = "W1971476217",
    references = "müller1991upper"
}

The Furongian (upper Cambrian) Leptoplastus Zone marks a time of critical changes in the evolution of olenid trilobites. This zone, unexposed at Andrarum in Skåne, southern Sweden, has been re-excavated and the sequence of faunas and sediments logged in detail. The faunal succession accords with that previously described from borehole cores by Westergård, and the subzones of L. paucisegmentatus, L. raphidophorus, L. crassicornis, L. ovatus, L. angustatus, and L. stenotus have been recognized. In the first two subzones the olenid assemblages are monospecific. At the base of the L. crassicornis Subzone more than one species is present and morphotypes with long genal spines appear for the first time. Faunal turnover is rapid, but the incoming of new species is invariably linked to an abrupt change in sedimentation, or follows an unfossiliferous interval; species either arose or migrated in after a time of environmental perturbation. Particular faunal associations are often confined to discrete sedimentary packages though some species may range through a succession of sedimentary changes. Leptoplastus crassicornis has very long genal spines, adapted for resting on the sea floor; it may have competed with the coeval, and very similar, L. angustatus. Subsequently, L. angustatus is accompanied by the stout-bodied, short-spined L. ovatus, which presumably occupied a different niche within the same environment. Leptoplastus stenotus is convergent on the much earlier L. paucisegmentatus, and likewise is found as a monospecific assemblage, presumably being adapted to a similar niche.

@article{doi10108000241160600623731,
    author = "Ahlberg, Per and Månsson, Kristina and Clarkson, Euan N. K. and Taylor, Cecilia M.",
    title = "Faunal turnovers and trilobite morphologies in the upper Cambrian Leptoplastus Zone at Andrarum, southern Sweden",
    year = "2006",
    journal = "Lethaia",
    abstract = "The Furongian (upper Cambrian) Leptoplastus Zone marks a time of critical changes in the evolution of olenid trilobites. This zone, unexposed at Andrarum in Skåne, southern Sweden, has been re-excavated and the sequence of faunas and sediments logged in detail. The faunal succession accords with that previously described from borehole cores by Westergård, and the subzones of L. paucisegmentatus, L. raphidophorus, L. crassicornis, L. ovatus, L. angustatus, and L. stenotus have been recognized. In the first two subzones the olenid assemblages are monospecific. At the base of the L. crassicornis Subzone more than one species is present and morphotypes with long genal spines appear for the first time. Faunal turnover is rapid, but the incoming of new species is invariably linked to an abrupt change in sedimentation, or follows an unfossiliferous interval; species either arose or migrated in after a time of environmental perturbation. Particular faunal associations are often confined to discrete sedimentary packages though some species may range through a succession of sedimentary changes. Leptoplastus crassicornis has very long genal spines, adapted for resting on the sea floor; it may have competed with the coeval, and very similar, L. angustatus. Subsequently, L. angustatus is accompanied by the stout-bodied, short-spined L. ovatus, which presumably occupied a different niche within the same environment. Leptoplastus stenotus is convergent on the much earlier L. paucisegmentatus, and likewise is found as a monospecific assemblage, presumably being adapted to a similar niche.",
    url = "https://doi.org/10.1080/00241160600623731",
    doi = "10.1080/00241160600623731",
    openalex = "W2076100793",
    references = "aldridge1992upper, doi101007bf02989434, doi101017s0263593300002133, doi101017s0263593300010427, doi10108000241160410002081, doi101111j1469185x1986tb00464x, doi101111j150239312001tb00056x, doi101344105000001599, doi1018814epiiugs2000v23i3006, doi1037570bgsd20004703, doi105281zenodo16089111, maas2003morphology, openalexw2131107865, openalexw353142951"
}

A diverse and well-preserved fauna of shelly fossils from the upper Lower Cambrian Bastion and Ella Island Formations of North-East Greenland contains more than 90 species. The fauna is the most diverse shelly fauna yet discovered in the Lower Cambrian of Laurentia and includes many fossils previously known only from other continental blocks. It enhances correlation of the North-East Greenland succession into Laurentia, most notably with the Browns Pond Formation of New York State, but also with other important Early Cambrian continents, in particular with Australia, Antarctica, and Siberia. A middle Dyeran age is most probable for both the Bastion and Ella Island Formation, and the rich fossil assemblage facilitates correlation with the Botoman Stage of Siberia and its equivalents. One new taxon is described, the disc-shaped problematicum Tunudiscus duovittarius n. gen. and sp.

@article{doi101666002233602006801087ssfftu20co2,
    author = "Skovsted, Christian B.",
    title = "SMALL SHELLY FAUNA FROM THE UPPER LOWER CAMBRIAN BASTION AND ELLA ISLAND FORMATIONS, NORTH-EAST GREENLAND",
    year = "2006",
    journal = "Journal of Paleontology",
    abstract = "A diverse and well-preserved fauna of shelly fossils from the upper Lower Cambrian Bastion and Ella Island Formations of North-East Greenland contains more than 90 species. The fauna is the most diverse shelly fauna yet discovered in the Lower Cambrian of Laurentia and includes many fossils previously known only from other continental blocks. It enhances correlation of the North-East Greenland succession into Laurentia, most notably with the Browns Pond Formation of New York State, but also with other important Early Cambrian continents, in particular with Australia, Antarctica, and Siberia. A middle Dyeran age is most probable for both the Bastion and Ella Island Formation, and the rich fossil assemblage facilitates correlation with the Botoman Stage of Siberia and its equivalents. One new taxon is described, the disc-shaped problematicum Tunudiscus duovittarius n. gen. and sp.",
    url = "https://doi.org/10.1666/0022-3360(2006)80[1087:ssfftu]2.0.co;2",
    doi = "10.1666/0022-3360(2006)80[1087:ssfftu]2.0.co;2",
    openalex = "W2240717407",
    references = "doi101111j150239311993tb01502x, doi105479si009638011395227, ulrich1931cambrian"
}

The middle Cambrian -Furongian transitional interval was a time of significant biotic and environmental changes. Strata of this age in Scania, southern Sweden, contain two interlayered biofacies, a normal one dominated by trilobites and an anomalous one dominated by phosphatocopines (small bivalved arthropods). In places these biofacies are separated by intervals barren of fossils. In a phosphatocopine facies without trilobites in the upper Agnostus pisiformis Zone at Andrarum we recovered scattered fossil aggregates with a homogeneous composition of tightly packed and stacked phosphatocopines. These aggregates are interpreted as coprolites produced by an undetermined predator, possibly the chaetognath-like protoconodont animal or some other softbodied metazoan. The so-called barren intervals of Scania are not necessarily barren of fossils, but only trilobites, brachiopods, and other skeletal elements with a calcium-carbonate composition. The phosphatocopine facies with coprolites in the uppermost part of the A. pisiformis Zone correlates with the trilobite mass extinction at the top of the Marjumiid Biomere in Laurentia and immediately prior to the onset of the Steptoean Positive Carbon Isotope Excursion (SPICE), inferring a global shift in the oceanic chemistry that in Scania favoured phosphatocopines over the more common, trilobite-dominated faunas.

@article{doi101111j15023931200600007x,
    author = "Eriksson, Mats E. and Terfelt, Fredrik",
    title = "Anomalous facies and ancient faeces in the latest middle Cambrian of Sweden",
    year = "2007",
    journal = "Lethaia",
    abstract = "The middle Cambrian -Furongian transitional interval was a time of significant biotic and environmental changes. Strata of this age in Scania, southern Sweden, contain two interlayered biofacies, a normal one dominated by trilobites and an anomalous one dominated by phosphatocopines (small bivalved arthropods). In places these biofacies are separated by intervals barren of fossils. In a phosphatocopine facies without trilobites in the upper Agnostus pisiformis Zone at Andrarum we recovered scattered fossil aggregates with a homogeneous composition of tightly packed and stacked phosphatocopines. These aggregates are interpreted as coprolites produced by an undetermined predator, possibly the chaetognath-like protoconodont animal or some other softbodied metazoan. The so-called barren intervals of Scania are not necessarily barren of fossils, but only trilobites, brachiopods, and other skeletal elements with a calcium-carbonate composition. The phosphatocopine facies with coprolites in the uppermost part of the A. pisiformis Zone correlates with the trilobite mass extinction at the top of the Marjumiid Biomere in Laurentia and immediately prior to the onset of the Steptoean Positive Carbon Isotope Excursion (SPICE), inferring a global shift in the oceanic chemistry that in Scania favoured phosphatocopines over the more common, trilobite-dominated faunas.",
    url = "https://doi.org/10.1111/j.1502-3931.2006.00007.x",
    doi = "10.1111/j.1502-3931.2006.00007.x",
    openalex = "W1806781834",
    references = "doi10108000241160600623731, doi1037570bgsd20004703"
}

The ability of a 650 base pair section of the mitochondrial cytochrome c oxidase I (COI) gene to provide species-level identifications has been demonstrated for large taxonomic assemblages of animals such as insects, birds, and fishes, but not for the subphylum Crustacea, one of the most diverse groups of arthropods. In this study, we test the ability of COI to provide identifications in this group, examining two disparate levels in the taxonomic hierarchy — orders and species. The first phase of our study involved the development of a sequence profile for 23 dominant crustacean orders, based upon the analysis of 150 species, each belonging to a different family. The COI amino acid data placed these taxa into cohesive assemblages whose membership coincided with currently accepted boundaries at the order, superorder, and subclass levels. Species-level resolution was subsequently examined in an assemblage of Decapoda and in representatives of the genera Daphnia (Cladocera) and Gammarus (Amphipoda). These studies revealed that levels of nucleotide sequence divergence were from 19 to 48 times greater between congeneric species than between individuals of a species. We conclude that sequence variation in the COI barcode region will be very effective for discriminating species of Crustacea.

@article{doi101139f07008,
    author = "Costa, Filipe O. and deWaard, Jeremy R and Boutillier, James A. and Ratnasingham, Sujeevan and Dooh, Robert T and Hajibabaei, Mehrdad and Hebert, Paul D. N.",
    title = "Biological identifications through DNA barcodes: the case of the Crustacea",
    year = "2007",
    journal = "Canadian Journal of Fisheries and Aquatic Sciences",
    abstract = "The ability of a 650 base pair section of the mitochondrial cytochrome c oxidase I (COI) gene to provide species-level identifications has been demonstrated for large taxonomic assemblages of animals such as insects, birds, and fishes, but not for the subphylum Crustacea, one of the most diverse groups of arthropods. In this study, we test the ability of COI to provide identifications in this group, examining two disparate levels in the taxonomic hierarchy — orders and species. The first phase of our study involved the development of a sequence profile for 23 dominant crustacean orders, based upon the analysis of 150 species, each belonging to a different family. The COI amino acid data placed these taxa into cohesive assemblages whose membership coincided with currently accepted boundaries at the order, superorder, and subclass levels. Species-level resolution was subsequently examined in an assemblage of Decapoda and in representatives of the genera Daphnia (Cladocera) and Gammarus (Amphipoda). These studies revealed that levels of nucleotide sequence divergence were from 19 to 48 times greater between congeneric species than between individuals of a species. We conclude that sequence variation in the COI barcode region will be very effective for discriminating species of Crustacea.",
    url = "https://doi.org/10.1139/f07-008",
    doi = "10.1139/f07-008",
    openalex = "W2126580086",
    references = "openalexw1586553371"
}

Three species of bradoriid arthropods from the lower to middle Cambrian transitional interval of Scania, southern Sweden, are described and illustrated: Beyrichona tinea from the top of the traditional lower Cambrian (Gislv Formation; Ornamentaspis? linnarssoni Zone), and Hipponicharion eos and Alutella sp. from the basal portion of the traditional middle Cambrian (lowermost part of the Alum Shale Formation). The bradoriid fauna compares most closely with others previously described from western and eastern Avalonia (New Brunswick and England). The record of B. tinea suggests a correlation between the "Protolenus Zone" (Hupeolenus Zone) of western Avalonia and the O.? linnarssoni Zone of Scandinavia. Hipponicharion eos appears to be a fairly long-ranging species as it has previously been recorded from upper lower Cambrian or lower middle Cambrian strata in New Brunswick, Poland, and probably Sardinia. The record of H. eos from the lowermost part of the Alum Shale Formation suggests that this largely unfossiliferous interval in the Scanian succession is not younger than the Acadoparadoxides oelandicus Superzone. The genus Alutella has not previously been recorded from the Acado-Baltic Province.

@article{doi104202app20080409,
    author = "Álvarez, María Eugenia Dies and Gozalo, Rodolfo and Cederström, Peter and Ahlberg, Per",
    title = "Bradoriid Arthropods from the Lower-Middle Cambrian of Scania, Sweden",
    year = "2008",
    journal = "Acta Palaeontologica Polonica",
    abstract = {Three species of bradoriid arthropods from the lower to middle Cambrian transitional interval of Scania, southern Sweden, are described and illustrated: Beyrichona tinea from the top of the traditional lower Cambrian (Gislv Formation; Ornamentaspis? linnarssoni Zone), and Hipponicharion eos and Alutella sp. from the basal portion of the traditional middle Cambrian (lowermost part of the Alum Shale Formation). The bradoriid fauna compares most closely with others previously described from western and eastern Avalonia (New Brunswick and England). The record of B. tinea suggests a correlation between the "Protolenus Zone" (Hupeolenus Zone) of western Avalonia and the O.? linnarssoni Zone of Scandinavia. Hipponicharion eos appears to be a fairly long-ranging species as it has previously been recorded from upper lower Cambrian or lower middle Cambrian strata in New Brunswick, Poland, and probably Sardinia. The record of H. eos from the lowermost part of the Alum Shale Formation suggests that this largely unfossiliferous interval in the Scanian succession is not younger than the Acadoparadoxides oelandicus Superzone. The genus Alutella has not previously been recorded from the Acado-Baltic Province.},
    url = "https://doi.org/10.4202/app.2008.0409",
    doi = "10.4202/app.2008.0409",
    openalex = "W2132997243",
    references = "ulrich1931cambrian"
}

Abstract Data on the first appearances of major animal groups with mineralized skeletons on the Siberian Platform and worldwide are revised and summarized herein with references to an improved carbon isotope stratigraphy and radiometric dating in order to reconstruct the Cambrian radiation (popularly known as the ‘Cambrian explosion’) with a higher precision and provide a basis for the definition of Cambrian Stages 2 to 4. The Lophotrochozoa and, probably, Chaetognatha were first among protostomians to achieve biomineralization during the Terreneuvian Epoch, mainly the Fortunian Age. Fast evolutionary radiation within the Lophotrochozoa was followed by radiation of the sclerotized and biomineralized Ecdysozoa during Stage 3. The first mineralized skeletons of the Deuterostomia, represented by echinoderms, appeared in the middle of Cambrian Stage 3. The fossil record of sponges and cnidarians suggests that they acquired biomineralized skeletons in the late Neoproterozoic, but diversification of both definite sponges and cnidarians was in parallel to that of bilaterians. The distribution of calcium carbonate skeletal mineralogies from the upper Ediacaran to lower Cambrian reflects fluctuations in the global ocean chemistry and shows that the Cambrian radiation occurred mainly during a time of aragonite and high-magnesium calcite seas.

@article{doi101017s0016756811000720,
    author = "Kouchinsky, Artem and Bengtson, Stefan and Runnegar, Bruce and Skovsted, Christian B. and Steiner, Michael and Vendrasco, Michael J.",
    title = "Chronology of early Cambrian biomineralization",
    year = "2011",
    journal = "Geological Magazine",
    abstract = "Abstract Data on the first appearances of major animal groups with mineralized skeletons on the Siberian Platform and worldwide are revised and summarized herein with references to an improved carbon isotope stratigraphy and radiometric dating in order to reconstruct the Cambrian radiation (popularly known as the ‘Cambrian explosion’) with a higher precision and provide a basis for the definition of Cambrian Stages 2 to 4. The Lophotrochozoa and, probably, Chaetognatha were first among protostomians to achieve biomineralization during the Terreneuvian Epoch, mainly the Fortunian Age. Fast evolutionary radiation within the Lophotrochozoa was followed by radiation of the sclerotized and biomineralized Ecdysozoa during Stage 3. The first mineralized skeletons of the Deuterostomia, represented by echinoderms, appeared in the middle of Cambrian Stage 3. The fossil record of sponges and cnidarians suggests that they acquired biomineralized skeletons in the late Neoproterozoic, but diversification of both definite sponges and cnidarians was in parallel to that of bilaterians. The distribution of calcium carbonate skeletal mineralogies from the upper Ediacaran to lower Cambrian reflects fluctuations in the global ocean chemistry and shows that the Cambrian radiation occurred mainly during a time of aragonite and high-magnesium calcite seas.",
    url = "https://doi.org/10.1017/s0016756811000720",
    doi = "10.1017/s0016756811000720",
    openalex = "W2127465210",
    references = "bengtson1976the, brasier1987microfossils, doi101002jemt10217, doi101002jezb21090, doi10100797814615074751, doi10100797814899242787, doi101016c20090644421, doi101016jpalaeo200401022, doi101016jpalaeo200703046, doi101016jpalaeo200902013, doi101016jpalwor200610014, doi101016s0031018298001096, doi101017s0022336000024963, doi101017s0022336000034879, doi101017s0022336000036465, doi101038326181a0, doi101038nature06614, doi101038nature07673, doi101093icb431166, doi101098rspb20063761, doi101111j109636421995tb00110x, doi101111j150239311975tb01311x, doi101111j150239311999tb00547x, doi101126science1107765, doi101126science2705236598, doi101127zdgg1111959434, doi101130g25094a1, doi101146annurevearth33092203122519, doi101666100651, doi10182618200067378198301, doi101826182003741571989, doi104202app20090058, doi105860choice304422, doi105860choice465038, doi105962bhltitle66379, morris1987a, openalexw2473761340, openalexw2598873191, openalexw3127114020, openalexw587905045, tiwari1999organicwalled"
}

Background: Decapods are the most recognizable of all crustaceans and comprise a dominant group of benthic invertebrates of the continental shelf and slope, including many species of economic importance. Of the 17635 morphologically described Decapoda species, only 5.4% are represented by COI barcode region sequences. It therefore remains a challenge to compile regional databases that identify and analyse the extent and patterns of decapod diversity throughout the world.

@article{doi101371journalpone0019449,
    author = "da Silva, Joana Matzen and Creer, Simon and Santos, Antonina Dos and Costa, Ana C. and Cunha, Marina R. and Costa, Filipe O. and Carvalho, Gary R.",
    title = "Systematic and Evolutionary Insights Derived from mtDNA COI Barcode Diversity in the Decapoda (Crustacea: Malacostraca)",
    year = "2011",
    journal = "PLoS ONE",
    abstract = "Background: Decapods are the most recognizable of all crustaceans and comprise a dominant group of benthic invertebrates of the continental shelf and slope, including many species of economic importance. Of the 17635 morphologically described Decapoda species, only 5.4\% are represented by COI barcode region sequences. It therefore remains a challenge to compile regional databases that identify and analyse the extent and patterns of decapod diversity throughout the world.",
    url = "https://doi.org/10.1371/journal.pone.0019449",
    doi = "10.1371/journal.pone.0019449",
    openalex = "W2128927389",
    references = "openalexw1586553371"
}

Abstract: The ontogeny of the trilobite Protopeltura aciculata (Angelin, 1854) is described on the basis of material from the upper Cambrian (Furongian) of Andrarum (Skåne) and Hjelmsäter (Västergötland), Sweden. P. aciculata is present in the Parabolina brevispina and Parabolina spinulosa zones. Protopeltura aciculata is represented by all stages of growth, from early protaspides to holaspides, although most of the specimens are disarticulated and precise degrees are unknown. The cranidia have therefore been allocated to five morphological groups. Cuticular sculpture of the cranidia changes throughout ontogeny. Large tubercles are present in earlier stages, disappear gradually in middle meraspid stages and are replaced with a very faint granulation. The transitory pygidium, relatively large and shield‐shaped with upwardly and backwardly directed marginal spines in early meraspides, later becomes very small, triangular‐shaped and lacking spines as a late meraspid and holaspid. The development of hypostomes and librigenae is also described. Protopeltura aciculata shows major intraspecific variations throughout development, especially regarding the pygidium where variation is much less constrained than in many other olenids. This high developmental plasticity may be a survival strategy for a trilobite living in a stressed environment. Protopeltura inhabited a dysoxic environment, possibly unusually prone to localised spreading of anoxic or toxic water. Some morphs may have been less vulnerable than others to such stresses, surviving by chance and thus enabling the species to continue.

@article{doi101111j14754983201201162x,
    author = "Månsson, Kristina and Clarkson, Euan N. K.",
    title = "Ontogeny of the Upper Cambrian (Furongian) Olenid trilobite Protopeltura aciculate (Angelin, 1854) from Skåne and Västergötland, Sweden",
    year = "2012",
    journal = "Palaeontology",
    abstract = "Abstract: The ontogeny of the trilobite Protopeltura aciculata (Angelin, 1854) is described on the basis of material from the upper Cambrian (Furongian) of Andrarum (Skåne) and Hjelmsäter (Västergötland), Sweden. P. aciculata is present in the Parabolina brevispina and Parabolina spinulosa zones. Protopeltura aciculata is represented by all stages of growth, from early protaspides to holaspides, although most of the specimens are disarticulated and precise degrees are unknown. The cranidia have therefore been allocated to five morphological groups. Cuticular sculpture of the cranidia changes throughout ontogeny. Large tubercles are present in earlier stages, disappear gradually in middle meraspid stages and are replaced with a very faint granulation. The transitory pygidium, relatively large and shield‐shaped with upwardly and backwardly directed marginal spines in early meraspides, later becomes very small, triangular‐shaped and lacking spines as a late meraspid and holaspid. The development of hypostomes and librigenae is also described. Protopeltura aciculata shows major intraspecific variations throughout development, especially regarding the pygidium where variation is much less constrained than in many other olenids. This high developmental plasticity may be a survival strategy for a trilobite living in a stressed environment. Protopeltura inhabited a dysoxic environment, possibly unusually prone to localised spreading of anoxic or toxic water. Some morphs may have been less vulnerable than others to such stresses, surviving by chance and thus enabling the species to continue.",
    url = "https://doi.org/10.1111/j.1475-4983.2012.01162.x",
    doi = "10.1111/j.1475-4983.2012.01162.x",
    openalex = "W1517613897",
    references = "doi10108000241160600623731, doi1037570bgsd20004703"
}

BACKGROUND: The evolutionary history and relationships of the mud shrimps (Crustacea: Decapoda: Gebiidea and Axiidea) are contentious, with previous attempts revealing mixed results. The mud shrimps were once classified in the infraorder Thalassinidea. Recent molecular phylogenetic analyses, however, suggest separation of the group into two individual infraorders, Gebiidea and Axiidea. Mitochondrial (mt) genome sequence and structure can be especially powerful in resolving higher systematic relationships that may offer new insights into the phylogeny of the mud shrimps and the other decapod infraorders, and test the hypothesis of dividing the mud shrimps into two infraorders. RESULTS: We present the complete mitochondrial genome sequences of five mud shrimps, Austinogebia edulis, Upogebia major, Thalassina kelanang (Gebiidea), Nihonotrypaea thermophilus and Neaxius glyptocercus (Axiidea). All five genomes encode a standard set of 13 protein-coding genes, two ribosomal RNA genes, 22 transfer RNA genes and a putative control region. Except for T. kelanang, mud shrimp mitochondrial genomes exhibited rearrangements and novel patterns compared to the pancrustacean ground pattern. Each of the two Gebiidea species (A. edulis and U. major) and two Axiidea species (N. glyptocercus and N. thermophiles) share unique gene order specific to their infraorders and analyses further suggest these two derived gene orders have evolved independently. Phylogenetic analyses based on the concatenated nucleotide and amino acid sequences of 13 protein-coding genes indicate the possible polyphyly of mud shrimps, supporting the division of the group into two infraorders. However, the infraordinal relationships among the Gebiidea and Axiidea, and other reptants are poorly resolved. The inclusion of mt genome from more taxa, in particular the reptant infraorders Polychelida and Glypheidea is required in further analysis. CONCLUSIONS: Phylogenetic analyses on the mt genome sequences and the distinct gene orders provide further evidences for the divergence between the two mud shrimp infraorders, Gebiidea and Axiidea, corroborating previous molecular phylogeny and justifying their infraordinal status. Mitochondrial genome sequences appear to be promising markers for resolving phylogenetic issues concerning decapod crustaceans that warrant further investigations and our present study has also provided further information concerning the mt genome evolution of the Decapoda.

@article{doi1011861471216413631,
    author = "Lin, Feng-Jiau and Liu, Yuan and Sha, Zhongli and Tsang, Ling Ming and Chu, Ka Hou and Chan, Tin‐Yam and Liu, Ruiyu and Cui, Zhaoxia",
    title = "Evolution and phylogeny of the mud shrimps (Crustacea: Decapoda) revealed from complete mitochondrial genomes",
    year = "2012",
    journal = "BMC Genomics",
    abstract = "BACKGROUND: The evolutionary history and relationships of the mud shrimps (Crustacea: Decapoda: Gebiidea and Axiidea) are contentious, with previous attempts revealing mixed results. The mud shrimps were once classified in the infraorder Thalassinidea. Recent molecular phylogenetic analyses, however, suggest separation of the group into two individual infraorders, Gebiidea and Axiidea. Mitochondrial (mt) genome sequence and structure can be especially powerful in resolving higher systematic relationships that may offer new insights into the phylogeny of the mud shrimps and the other decapod infraorders, and test the hypothesis of dividing the mud shrimps into two infraorders. RESULTS: We present the complete mitochondrial genome sequences of five mud shrimps, Austinogebia edulis, Upogebia major, Thalassina kelanang (Gebiidea), Nihonotrypaea thermophilus and Neaxius glyptocercus (Axiidea). All five genomes encode a standard set of 13 protein-coding genes, two ribosomal RNA genes, 22 transfer RNA genes and a putative control region. Except for T. kelanang, mud shrimp mitochondrial genomes exhibited rearrangements and novel patterns compared to the pancrustacean ground pattern. Each of the two Gebiidea species (A. edulis and U. major) and two Axiidea species (N. glyptocercus and N. thermophiles) share unique gene order specific to their infraorders and analyses further suggest these two derived gene orders have evolved independently. Phylogenetic analyses based on the concatenated nucleotide and amino acid sequences of 13 protein-coding genes indicate the possible polyphyly of mud shrimps, supporting the division of the group into two infraorders. However, the infraordinal relationships among the Gebiidea and Axiidea, and other reptants are poorly resolved. The inclusion of mt genome from more taxa, in particular the reptant infraorders Polychelida and Glypheidea is required in further analysis. CONCLUSIONS: Phylogenetic analyses on the mt genome sequences and the distinct gene orders provide further evidences for the divergence between the two mud shrimp infraorders, Gebiidea and Axiidea, corroborating previous molecular phylogeny and justifying their infraordinal status. Mitochondrial genome sequences appear to be promising markers for resolving phylogenetic issues concerning decapod crustaceans that warrant further investigations and our present study has also provided further information concerning the mt genome evolution of the Decapoda.",
    url = "https://doi.org/10.1186/1471-2164-13-631",
    doi = "10.1186/1471-2164-13-631",
    openalex = "W2002854652",
    references = "openalexw566092230"
}

The world-famous 'Orsten' Konservat-Lagerstätte has yielded detailed information about Cambrian arthropods and their morphology. Internal organs or soft tissues have, however, rarely been reported, an obvious palaeobiological drawback. In this study, we employed synchrotron radiation X-ray tomographic microscopy (SRXTM) to study microscopic 'Orsten' arthropods from the Cambrian of Sweden: Skara minuta and two phosphatocopine species, Hesslandona sp. and Hesslandona trituberculata. This exceptionally high-resolution technique reveals internal organs or soft tissues that allow detailed comparison with equivalent structures in extant crustaceans and functional inferences to be made. The S. minuta specimen shows the digestive system and muscles that extend to the extremities. The slanting anterior portion of the head and anterior position of the mouth with a straight oesophagus suggest a primarily brushing and scraping way of feeding. The prominent head appendage muscles indicate muscle strength and good capacity for food manipulation. In the phosphatocopines the bulbous labrum is one of the most prominent morphological structures of the body. All specimens analysed reveal pairs of muscle bundles within the labrum. Based on comparisons with extant crustacean relatives, these muscles would fulfil the function of moving the labrum up and down in order to open the buccal cavity. The results of this pilot study demonstrate that there is still much to be learned about the 'Orsten' taxa.

@article{doi101371journalpone0042582,
    author = "Eriksson, Mats E. and Terfelt, Fredrik and Elofsson, Rolf and Marone, Federica",
    title = "Internal Soft-Tissue Anatomy of Cambrian ‘Orsten’ Arthropods as Revealed by Synchrotron X-Ray Tomographic Microscopy",
    year = "2012",
    journal = "PLoS ONE",
    abstract = "The world-famous 'Orsten' Konservat-Lagerstätte has yielded detailed information about Cambrian arthropods and their morphology. Internal organs or soft tissues have, however, rarely been reported, an obvious palaeobiological drawback. In this study, we employed synchrotron radiation X-ray tomographic microscopy (SRXTM) to study microscopic 'Orsten' arthropods from the Cambrian of Sweden: Skara minuta and two phosphatocopine species, Hesslandona sp. and Hesslandona trituberculata. This exceptionally high-resolution technique reveals internal organs or soft tissues that allow detailed comparison with equivalent structures in extant crustaceans and functional inferences to be made. The S. minuta specimen shows the digestive system and muscles that extend to the extremities. The slanting anterior portion of the head and anterior position of the mouth with a straight oesophagus suggest a primarily brushing and scraping way of feeding. The prominent head appendage muscles indicate muscle strength and good capacity for food manipulation. In the phosphatocopines the bulbous labrum is one of the most prominent morphological structures of the body. All specimens analysed reveal pairs of muscle bundles within the labrum. Based on comparisons with extant crustacean relatives, these muscles would fulfil the function of moving the labrum up and down in order to open the buccal cavity. The results of this pilot study demonstrate that there is still much to be learned about the 'Orsten' taxa.",
    url = "https://doi.org/10.1371/journal.pone.0042582",
    doi = "10.1371/journal.pone.0042582",
    openalex = "W2013926980"
}

The Alum Shale Formation exposed at the Degerhamn quarry road section, southern Öland, Sweden, contains a diversified assemblage of euconodonts, paraconodonts and protoconodonts, the majority of which have ranges confined to the Furongian Series (Cambrian). The first occurrence (FO) of the cosmopolitan euconodont species Proconodontus muelleri is recorded in the uppermost part of the Ctenopyge spectabilis trilobite Zone and the first appearance datum of Cordylodus? andresi is in the upper part of the Parabolina lobata trilobite Zone. Three new successive paraconodont associations are introduced: (1) the Furnishina Association, (2) the Prooneotodus Association and (3) the Westergaardodina Association, which, respectively, correspond to deeper marine, deep marine and shallow marine conditions. The genus Stenodontus Chen & Gong is revised in multielement taxonomy. New species formally named are Furnishina holmi and Westergaardodina asinina; Furnishina sp. A and Furnishina sp. B are described in open nomenclature.

@article{doi101080110358972013858768,
    author = "Bagnoli, Gabriella and Stouge, Svend",
    title = "Upper Furongian (Cambrian) conodonts from the Degerhamn quarry road section, southern Öland, Sweden",
    year = "2014",
    journal = "GFF",
    abstract = "The Alum Shale Formation exposed at the Degerhamn quarry road section, southern Öland, Sweden, contains a diversified assemblage of euconodonts, paraconodonts and protoconodonts, the majority of which have ranges confined to the Furongian Series (Cambrian). The first occurrence (FO) of the cosmopolitan euconodont species Proconodontus muelleri is recorded in the uppermost part of the Ctenopyge spectabilis trilobite Zone and the first appearance datum of Cordylodus? andresi is in the upper part of the Parabolina lobata trilobite Zone. Three new successive paraconodont associations are introduced: (1) the Furnishina Association, (2) the Prooneotodus Association and (3) the Westergaardodina Association, which, respectively, correspond to deeper marine, deep marine and shallow marine conditions. The genus Stenodontus Chen \& Gong is revised in multielement taxonomy. New species formally named are Furnishina holmi and Westergaardodina asinina; Furnishina sp. A and Furnishina sp. B are described in open nomenclature.",
    url = "https://doi.org/10.1080/11035897.2013.858768",
    doi = "10.1080/11035897.2013.858768",
    openalex = "W2046822722",
    references = "doi10108000241160600623731, doi103140bullgeosci1270"
}

The traditional Furongian trilobite biozones of Scandinavia, recently proposed abandoned due to inconsistent boundary definitions [Terfelt, F., Eriksson, M.E., Ahlberg, P. & Babcock, L.E., 2008: Furongian Series (Cambrian) biostratigraphy of Scandinavia – a revision. Norwegian Journal of Geology88, 73–87], are resurrected and elevated to superzonal rank. These superzones are usually readily recognized in the field, even by non-specialists, and for general correlation and mapping the more wide-ranging biozones are considerably more practicable than the very detailed zonation (formerly subzonation) introduced by Terfelt et al. (2008). Formal definition of the superzones is outlined including designation of stratotype sections. The superzones are each defined by the FAD of a characterizing species group and upwards delimited by the base of the succeeding superzone. The long used Olenus, Parabolina and Leptoplastus (super)zones as well as the recently introduced Acerocarina Superzone (= Acerocare Zone of older literature) are maintained and formalized. The Protopeltura praecursor, Peltura minor and Peltura scarabaeoides zones are abandoned and replaced by two new units, named the Protopeltura and Peltura superzones, respectively. Accordingly, all Furongian superzones have a uniform naming style referring to a characteristic genus. The six Furongian superzones currently comprise 27 trilobite zones. The Paradoxides forchhammeri Superzone (Cambrian Series 3) is extended upwards to the base of the Olenus Superzone, thereby formally including the Agnostus pisiformis Zone.

@article{doi101080110358972013878748,
    author = "Nielsen, Arne Thorshøj and Weidner, Thomas and Terfelt, Fredrik and Høyberget, Magne",
    title = "Upper Cambrian (Furongian) biostratigraphy in Scandinavia revisited: definition of superzones",
    year = "2014",
    journal = "GFF",
    abstract = "The traditional Furongian trilobite biozones of Scandinavia, recently proposed abandoned due to inconsistent boundary definitions [Terfelt, F., Eriksson, M.E., Ahlberg, P. \& Babcock, L.E., 2008: Furongian Series (Cambrian) biostratigraphy of Scandinavia – a revision. Norwegian Journal of Geology88, 73–87], are resurrected and elevated to superzonal rank. These superzones are usually readily recognized in the field, even by non-specialists, and for general correlation and mapping the more wide-ranging biozones are considerably more practicable than the very detailed zonation (formerly subzonation) introduced by Terfelt et al. (2008). Formal definition of the superzones is outlined including designation of stratotype sections. The superzones are each defined by the FAD of a characterizing species group and upwards delimited by the base of the succeeding superzone. The long used Olenus, Parabolina and Leptoplastus (super)zones as well as the recently introduced Acerocarina Superzone (= Acerocare Zone of older literature) are maintained and formalized. The Protopeltura praecursor, Peltura minor and Peltura scarabaeoides zones are abandoned and replaced by two new units, named the Protopeltura and Peltura superzones, respectively. Accordingly, all Furongian superzones have a uniform naming style referring to a characteristic genus. The six Furongian superzones currently comprise 27 trilobite zones. The Paradoxides forchhammeri Superzone (Cambrian Series 3) is extended upwards to the base of the Olenus Superzone, thereby formally including the Agnostus pisiformis Zone.",
    url = "https://doi.org/10.1080/11035897.2013.878748",
    doi = "10.1080/11035897.2013.878748",
    openalex = "W1991923586",
    references = "doi10108000241160600623731"
}

Crabs of the infra-order Brachyura are one of the most diverse groups of crustaceans with approximately 7,000 described species in 98 families, occurring in marine, freshwater, and terrestrial habitats. The relationships among the brachyuran families are poorly understood due to the high morphological complexity of the group. Here, we reconstruct the most comprehensive phylogeny of Brachyura to date using sequence data of six nuclear protein-coding genes and two mitochondrial rRNA genes from more than 140 species belonging to 58 families. The gene tree confirms that the "Podotremata," are paraphyletic. Within the monophyletic Eubrachyura, the reciprocal monophyly of the two subsections, Heterotremata and Thoracotremata, is supported. Monophyly of many superfamilies, however, is not recovered, indicating the prevalence of morphological convergence and the need for further taxonomic studies. Freshwater crabs were derived early in the evolution of Eubrachyura and are shown to have at least two independent origins. Bayesian relaxed molecular methods estimate that freshwater crabs separated from their closest marine sister taxa ~135 Ma, that is, after the break up of Pangaea (∼200 Ma) and that a Gondwanan origin of these freshwater representatives is untenable. Most extant families and superfamilies arose during the late Cretaceous and early Tertiary.

@article{doi101093molbevmsu068,
    author = "Tsang, Ling Ming and Schubart, Christoph D. and Ahyong, Shane T. and Lai, Joelle C. Y. and Au, Eugene Y.C. and Chan, Tin‐Yam and Ng, Peter K. L. and Chu, Ka Hou",
    title = "Evolutionary History of True Crabs (Crustacea: Decapoda: Brachyura) and the Origin of Freshwater Crabs",
    year = "2014",
    journal = "Molecular Biology and Evolution",
    abstract = {Crabs of the infra-order Brachyura are one of the most diverse groups of crustaceans with approximately 7,000 described species in 98 families, occurring in marine, freshwater, and terrestrial habitats. The relationships among the brachyuran families are poorly understood due to the high morphological complexity of the group. Here, we reconstruct the most comprehensive phylogeny of Brachyura to date using sequence data of six nuclear protein-coding genes and two mitochondrial rRNA genes from more than 140 species belonging to 58 families. The gene tree confirms that the "Podotremata," are paraphyletic. Within the monophyletic Eubrachyura, the reciprocal monophyly of the two subsections, Heterotremata and Thoracotremata, is supported. Monophyly of many superfamilies, however, is not recovered, indicating the prevalence of morphological convergence and the need for further taxonomic studies. Freshwater crabs were derived early in the evolution of Eubrachyura and are shown to have at least two independent origins. Bayesian relaxed molecular methods estimate that freshwater crabs separated from their closest marine sister taxa \textasciitilde 135 Ma, that is, after the break up of Pangaea (∼200 Ma) and that a Gondwanan origin of these freshwater representatives is untenable. Most extant families and superfamilies arose during the late Cretaceous and early Tertiary.},
    url = "https://doi.org/10.1093/molbev/msu068",
    doi = "10.1093/molbev/msu068",
    openalex = "W2170145114",
    references = "openalexw1586553371"
}

The concept of the agnostoid arthropod species Lotagnostus americanus (Billings, 1860), which has been reported from numerous localities in the upper Furongian Series (Cambrian) of Laurentia, Gondwana, Baltica, Avalonia, and Siberia, is reviewed with emphasis on morphologic and taphonomic information afforded by large collections from Hunan in South China, Xinjiang in Northwest China, and Zhejiang in Southeast China. Comparisons are made with type and topotype material from Quebec, Canada, as well as material from elsewhere in Canada, the USA, the United Kingdom, Sweden, Russia, and Kazakhstan. The new information clarifies the limits of morphologic variability in L. americanus owing to ontogenetic changes and variation within holaspides, including inferred microevolution. It also provides details on apparent variation of taphonomic origin. The Chinese collections demonstrate a moderately wide variation in L. americanus, indicating that arguments favoring restriction of Lotagnostus species to narrowly defined, geographically restricted forms are unwarranted. Species described as L. trisectus (Salter, 1864), L. asiaticus Troedsson, 1937, and L. punctatus Lu, 1964, for example, fall within the range of variation observed in L. americanus, and are regarded as junior synonyms. The effaced form Lotagnosilis obscurus Palmer, 1955 is removed from synonymy with L. americanus. A review of the stratigraphic distribution of L. americanus as construed here shows that the earliest occurrences of the species in all regions of the world are nearly synchronous.

@article{doi103140bullgeosci1500,
    author = "Peng, Shanchi and Babcock, Loren E. and Zhu, Xuejian and Ahlberg, Per and Terfelt, Fredrik and Dai, Tao",
    title = "Intraspecific variation and taphonomic alteration in the Cambrian (Furongian) agnostoid Lotagnostus americanus: new information from China",
    year = "2015",
    journal = "Bulletin of Geosciences",
    abstract = "The concept of the agnostoid arthropod species Lotagnostus americanus (Billings, 1860), which has been reported from numerous localities in the upper Furongian Series (Cambrian) of Laurentia, Gondwana, Baltica, Avalonia, and Siberia, is reviewed with emphasis on morphologic and taphonomic information afforded by large collections from Hunan in South China, Xinjiang in Northwest China, and Zhejiang in Southeast China. Comparisons are made with type and topotype material from Quebec, Canada, as well as material from elsewhere in Canada, the USA, the United Kingdom, Sweden, Russia, and Kazakhstan. The new information clarifies the limits of morphologic variability in L. americanus owing to ontogenetic changes and variation within holaspides, including inferred microevolution. It also provides details on apparent variation of taphonomic origin. The Chinese collections demonstrate a moderately wide variation in L. americanus, indicating that arguments favoring restriction of Lotagnostus species to narrowly defined, geographically restricted forms are unwarranted. Species described as L. trisectus (Salter, 1864), L. asiaticus Troedsson, 1937, and L. punctatus Lu, 1964, for example, fall within the range of variation observed in L. americanus, and are regarded as junior synonyms. The effaced form Lotagnosilis obscurus Palmer, 1955 is removed from synonymy with L. americanus. A review of the stratigraphic distribution of L. americanus as construed here shows that the earliest occurrences of the species in all regions of the world are nearly synchronous.",
    url = "https://doi.org/10.3140/bull.geosci.1500",
    doi = "10.3140/bull.geosci.1500",
    openalex = "W1998175800",
    references = "doi103140bullgeosci1270"
}

Pan, B., Skovsted, C.B., Sun, H.J. & Li, G.X., 18 June 2019. Biostratigraphical and palaeogeographical implications of Early Cambrian hyoliths from the North China Platform. Alcheringa 43, 351–380. ISSN 0311-5518.A succession of diverse hyolith assemblages comprising 10 genera and 14 species are reported from the lower Cambrian Shangwan and Sanjianfang sections of the Xinji Formation, and Xiaomeiyao section of the Houjiashan Formation, which crop out along the southern margin of the North China Platform. Most of the specimens are represented by both conchs and opercula. The identified orthothecids include Conotheca australiensis, Cupitheca holocyclata, C. costellata, Neogloborilus applanatus, N. spinatus, Tegminites hymenodes, Triplicatella disdoma, T. xinjia sp. nov. and Paratriplicatella shangwanensis gen. et sp. nov. The hyolithids comprise Protomicrocornus triplicensis gen. et sp. nov., Microcornus eximius, M. petilus, Parkula bounites and Parakorilithes mammillatus. Some anomalous taxa possess characteristics of both Hyolithida and Orthothecida, such as C. australiensis, Neogloborilus and P. triplicensis. Protomicrocornus may constitute a sister group of other hyolithids. The teeth of Parkula bounites and clavicles of Parakorilithes mammillatus are documented for the first time. The hyolith assemblages from North China are probably coeval, and can be correlated with the Cambrian upper Stage 3–lower Stage 4. Many taxa are also globally distributed and have significant potential for biostratigraphical correlations. In accordance, the hyoliths from North China reveal closest compositional similarities to faunas from eastern Gondwana, and especially South Australia. However, some taxa are shared with Laurentian assemblages suggesting cosmopolitanism, and possibly planktonic larval dispersal.Bing Pan* [bpan@nigpas.ac.cn], State Key Laboratory of Palaeobiology and Stratigraphy, Nanjing Institute of Geology and Palaeontology and Center for Excellence in Life and Paleoenvironment, Chinese Academy of Sciences, Nanjing 210008, PR China; Christian B. Skovsted [christian.skovsted@nrm.se], Department of Palaeobiology, Swedish Museum of Natural History, Box 50007, SE-104 05 Stockholm, Sweden; Haijing Sun [hjsun1987@163.com], State Key Laboratory of Palaeobiology and Stratigraphy, Nanjing Institute of Geology and Palaeontology and Center for Excellence in Life and Paleoenvironment, Chinese Academy of Sciences, Nanjing 210008, PR China; Guoxiang Li [gxli@nigpas.ac.cn], State Key Laboratory of Palaeobiology and Stratigraphy, Nanjing Institute of Geology and Palaeontology and Center for Excellence in Life and Paleoenvironment, Chinese Academy of Sciences, Nanjing 210008, PR China. *Also affiliated with: University of Science and Technology of China, Hefei 230026, PR China and Department of Palaeobiology, Swedish Museum of Natural History, Box 50007, SE-104 05 Stockholm, Sweden.

@article{doi1010800311551820191577492,
    author = "Pan, Bing and Skovsted, Christian B. and Sun, Haijing and Li, Guoxiang",
    title = "Biostratigraphical and palaeogeographical implications of Early Cambrian hyoliths from the North China Platform",
    year = "2019",
    journal = "Alcheringa An Australasian Journal of Palaeontology",
    abstract = "Pan, B., Skovsted, C.B., Sun, H.J. \& Li, G.X., 18 June 2019. Biostratigraphical and palaeogeographical implications of Early Cambrian hyoliths from the North China Platform. Alcheringa 43, 351–380. ISSN 0311-5518.A succession of diverse hyolith assemblages comprising 10 genera and 14 species are reported from the lower Cambrian Shangwan and Sanjianfang sections of the Xinji Formation, and Xiaomeiyao section of the Houjiashan Formation, which crop out along the southern margin of the North China Platform. Most of the specimens are represented by both conchs and opercula. The identified orthothecids include Conotheca australiensis, Cupitheca holocyclata, C. costellata, Neogloborilus applanatus, N. spinatus, Tegminites hymenodes, Triplicatella disdoma, T. xinjia sp. nov. and Paratriplicatella shangwanensis gen. et sp. nov. The hyolithids comprise Protomicrocornus triplicensis gen. et sp. nov., Microcornus eximius, M. petilus, Parkula bounites and Parakorilithes mammillatus. Some anomalous taxa possess characteristics of both Hyolithida and Orthothecida, such as C. australiensis, Neogloborilus and P. triplicensis. Protomicrocornus may constitute a sister group of other hyolithids. The teeth of Parkula bounites and clavicles of Parakorilithes mammillatus are documented for the first time. The hyolith assemblages from North China are probably coeval, and can be correlated with the Cambrian upper Stage 3–lower Stage 4. Many taxa are also globally distributed and have significant potential for biostratigraphical correlations. In accordance, the hyoliths from North China reveal closest compositional similarities to faunas from eastern Gondwana, and especially South Australia. However, some taxa are shared with Laurentian assemblages suggesting cosmopolitanism, and possibly planktonic larval dispersal.Bing Pan* [bpan@nigpas.ac.cn], State Key Laboratory of Palaeobiology and Stratigraphy, Nanjing Institute of Geology and Palaeontology and Center for Excellence in Life and Paleoenvironment, Chinese Academy of Sciences, Nanjing 210008, PR China; Christian B. Skovsted [christian.skovsted@nrm.se], Department of Palaeobiology, Swedish Museum of Natural History, Box 50007, SE-104 05 Stockholm, Sweden; Haijing Sun [hjsun1987@163.com], State Key Laboratory of Palaeobiology and Stratigraphy, Nanjing Institute of Geology and Palaeontology and Center for Excellence in Life and Paleoenvironment, Chinese Academy of Sciences, Nanjing 210008, PR China; Guoxiang Li [gxli@nigpas.ac.cn], State Key Laboratory of Palaeobiology and Stratigraphy, Nanjing Institute of Geology and Palaeontology and Center for Excellence in Life and Paleoenvironment, Chinese Academy of Sciences, Nanjing 210008, PR China. *Also affiliated with: University of Science and Technology of China, Hefei 230026, PR China and Department of Palaeobiology, Swedish Museum of Natural History, Box 50007, SE-104 05 Stockholm, Sweden.",
    url = "https://doi.org/10.1080/03115518.2019.1577492",
    doi = "10.1080/03115518.2019.1577492",
    openalex = "W2950305063",
    references = "doi101017jpa201747, doi101080031155182010496529, doi10108003115519508619270, doi101134s0031030110080010, doi104202app20120004"
}

The zonation of the Furongian Alum Shale in Scandinavia, based on olenid trilobites, is reviewed and revised. The current scheme is rooted in a detailed zonation introduced in the late 1950s with subzones that subsequently have been elevated to zonal rank. Ten of these zones are difficult to recognize in all Alum Shale districts, and a revised zonation is proposed, focused on unambiguous identification throughout Scandinavia. The difficulties in recognizing zones in some districts mostly relate to biofacies differentiation. Representatives of Ctenopyge are, for instance, common in palaeo-offshore areas, whereas pelturines are rare in these settings and vice versa in palaeo-inboard settings. The following modifications of the olenid zonation are proposed: the Olenus scanicus Zone is renamed the O. scanicus–O. rotundatus Zone; the Ctenopyge similis and Ctenopyge spectabilis zones are replaced by the Sphaerophthalmus modestus–Sphaerophthalmus angustus Zone; the Ctenopyge tumida Zone is renamed the Peltura acutidens–Ctenopyge tumida Zone; the Peltura scarabaeoides Subzone is restored (as a zone) and replaces the Ctenopyge bisulcata and Ctenopyge linnarssoni zones. The Parabolina heres megalops (Sub)Zone is reinstated and replaces the Peltura paradoxa Zone; the Acerocarina granulata and P. costata zones are combined as the Acerocarina granulata–Peltura costata Zone. In addition, the name Proceratopyge nathorsti–Simulolenus alpha Zone is suggested for the polymerid zone corresponding to the upper Miaolingian Agnostus pisiformis Zone. The proposed changes reduce the number of Furongian Zones to 23, allocated to six superzones. No subzones are recognized, but some zones can potentially be subdivided for improved local correlation. The stratigraphical ranges of all Furongian olenid trilobites and agnostoids described from Scandinavia are summarized.

@article{doi101111let12370,
    author = "Nielsen, Arne Thorshøj and Høyberget, Magne and Ahlberg, Per",
    title = "The Furongian (upper Cambrian) Alum Shale of Scandinavia: revision of zonation",
    year = "2020",
    journal = "Lethaia",
    abstract = "The zonation of the Furongian Alum Shale in Scandinavia, based on olenid trilobites, is reviewed and revised. The current scheme is rooted in a detailed zonation introduced in the late 1950s with subzones that subsequently have been elevated to zonal rank. Ten of these zones are difficult to recognize in all Alum Shale districts, and a revised zonation is proposed, focused on unambiguous identification throughout Scandinavia. The difficulties in recognizing zones in some districts mostly relate to biofacies differentiation. Representatives of Ctenopyge are, for instance, common in palaeo-offshore areas, whereas pelturines are rare in these settings and vice versa in palaeo-inboard settings. The following modifications of the olenid zonation are proposed: the Olenus scanicus Zone is renamed the O. scanicus–O. rotundatus Zone; the Ctenopyge similis and Ctenopyge spectabilis zones are replaced by the Sphaerophthalmus modestus–Sphaerophthalmus angustus Zone; the Ctenopyge tumida Zone is renamed the Peltura acutidens–Ctenopyge tumida Zone; the Peltura scarabaeoides Subzone is restored (as a zone) and replaces the Ctenopyge bisulcata and Ctenopyge linnarssoni zones. The Parabolina heres megalops (Sub)Zone is reinstated and replaces the Peltura paradoxa Zone; the Acerocarina granulata and P. costata zones are combined as the Acerocarina granulata–Peltura costata Zone. In addition, the name Proceratopyge nathorsti–Simulolenus alpha Zone is suggested for the polymerid zone corresponding to the upper Miaolingian Agnostus pisiformis Zone. The proposed changes reduce the number of Furongian Zones to 23, allocated to six superzones. No subzones are recognized, but some zones can potentially be subdivided for improved local correlation. The stratigraphical ranges of all Furongian olenid trilobites and agnostoids described from Scandinavia are summarized.",
    url = "https://doi.org/10.1111/let.12370",
    doi = "10.1111/let.12370",
    openalex = "W3011653487",
    references = "doi101017s001675681400079x, doi10108000241160600623731"
}