cometadata/datacite-titles-descriptions-related-identifiers huggingface dataset:
DOI: 10.6084/m9.figshare.21276708
title: Phylogeny of the amphibamiform temnospondyls: the relationship of taxa known by adults, larvae and neotenes

description: The Amphibamiformes, small temnospondyls from late Palaeozoic rocks, have been increasingly considered as the stem-group of some or all extant amphibians (Lissamphibia). Their relationships have become intensely studied after the discovery of new taxa and the revision of poorly known ones, but understanding is hampered by the fact that amphibamiforms fall into two very distinct groups: (a) terrestrial taxa known by adults only (Amphibamidae, Micropholidae) and (b) aquatic taxa known by larvae and neotenic adults (Branchiosauridae). The Branchiosauridae were recognized as a clade supported by a suite of larval synapomorphies, but the unknown larval morphology of the terrestrial clades leaves the question open to whether some branchiosaurid apomorphies might have been more widely distributed. Recently, some branchiosaurid specimens from Nýřany (Czech Republic) were proposed to be larvae of olsoniforms and amphibamids, and together with a revision of ancient branchiosaurid-like taxa from the United States and France prompt a re-analysis of this issue. In a phylogenetic analysis of 48 taxa and 113 characters, the Branchiosauridae were found to be monophyletic and nest in an unresolved trichotomy with Amphibamidae and the putative relatives of Lissamphibia. The present analysis finds the hypothesized olsoniform larvae from Nýřany to be adults of <i>Branchiosaurus salamandroides</i>, whereas some of the larvae from Mazon Creek (Illinois, USA) are not branchiosaurids, but immature specimens of the amphibamid <i>Amphibamus grandiceps</i>. Within branchiosaurids, four clades have been identified: (a) the Carboniferous <i>Anthracobamus</i> clade (<i>Anthracobamus</i>, <i>Montceaubatrachus</i>), (b) the mostly Carboniferous Branchiosaurinae (<i>Branchiosaurus</i>, <i>Milnererpeton</i>) and two largely Permian clades, the newly defined Apateoninae (genus <i>Apateon</i>) and Leptorophinae (<i>Melanerpeton</i>, <i>Leptorophus</i>, <i>Schoenfelderpeton</i>) clade. Branchiosaurid evolution involved a trend towards an enhanced paedomorphosis, a modification of branchial teeth, and successive reduction of bone in the scales and pectoral girdle.
DOI: 10.6084/m9.figshare.20518461.v1
title: Towards a unifying systematic scheme of fossil and living billfishes (Teleostei, Istiophoridae)

description: Extant istiophorids are open ocean apex predators that are extensively studied due to their ecological importance and high values for fisheries. Nevertheless, little is known about their evolution because of a fragmentary fossil record and extremely difficult taxonomy of fossil species. Here, we present a new phylogenetic hypothesis covering fossil and living istiophorids. Our results demonstrate that istiophorid richness is larger than previously assumed, comprising eight genera with 20 species. The phylogenetic analysis shows that istiophorids are grouped into four clades: the <i>Istiophorus</i> clade, which includes the sailfish; the Machairostra clade, which comprises <i>Makaira</i> spp., including two new species from the late Miocene (†<i>Makaira colonense</i> sp. nov. and †<i>Makaira fierstini</i> sp. nov.); the Gracilorostra clade, which comprise all remaining istiophorids with exception of spearfishes and includes two new genera and one new species (†<i>Morgula donosochagrense</i> gen. et sp. nov. and †<i>Spathochoira calvertense</i> gen. et. comb. nov.); and the Tetrapturomorpha clade is composed of the spearfishes and the extinct †<i>Prototetrapturus courcelli</i> gen. et. comb. nov. The family Istiophoridae shows an evolutionary trend toward reduction of the premaxillary thickness and increasing the extension of narial cavities. This reduction is related to an increase of adipose tissues in the rostrum base probably driven by the presence of the oleofera gland, an organ involved in feeding, healing, endothermy and hydrophobic functions. Our phylogeny shows a direct relationship between the rostral and cranial shape explained by body size and feeding behaviour. The larger istiophorids have lateral apophysis and the larger spines of the vertebral column. The spearfishes represent the smaller species of the family, with the extant <i>Tetrapturus</i> spp. first appearing in the late Pliocene. The clade Tetrapturomorpha shows an extreme size reduction over time when compared with species of their sister clade Gracilorostra, demonstrating an evolutionary trend towards size reduction. http://zoobank.org/urn:lsid:zoobank.org:pub:D3D3B15B-36FA-42EB-98AD-FAF369D989EB
DOI: 10.6084/m9.figshare.21187764
title: Appendicular osteology of <i>Skorpiovenator bustingorryi</i> (Theropoda, Abelisauridae) with comments on phylogenetic features of abelisaurids

description: <i>Skorpiovenator bustingorryi</i> is a derived abelisaurid theropod represented by a fairly complete skeleton from the Late Cretaceous sedimentary beds of north-western Patagonia. Although some features were described in the original paper, mainly related to the skull, the appendicular anatomy remains undescribed. The aim of the present contribution is to provide a detailed description and analysis of the available appendicular bones, including comparisons with other ceratosaurian theropods close to <i>Skorpiovenator</i>. In this way, new autapomorphies emerged to further distinguish <i>Skorpiovenator</i> from its relatives. Furthermore, a comprehensive phylogenetic analysis was performed and several characteristics of the hind limb, in particular some of the autopodium, resulted in the identification of new apomorphic traits for Ceratosauria and Abelisauridae. These features might prove to be useful for future phylogenetic analyses and may help to resolve the still confusing and debated internal relationships of abelisaurid theropods.
DOI: 10.6084/m9.figshare.21187764.v1
title: Appendicular osteology of <i>Skorpiovenator bustingorryi</i> (Theropoda, Abelisauridae) with comments on phylogenetic features of abelisaurids

description: <i>Skorpiovenator bustingorryi</i> is a derived abelisaurid theropod represented by a fairly complete skeleton from the Late Cretaceous sedimentary beds of north-western Patagonia. Although some features were described in the original paper, mainly related to the skull, the appendicular anatomy remains undescribed. The aim of the present contribution is to provide a detailed description and analysis of the available appendicular bones, including comparisons with other ceratosaurian theropods close to <i>Skorpiovenator</i>. In this way, new autapomorphies emerged to further distinguish <i>Skorpiovenator</i> from its relatives. Furthermore, a comprehensive phylogenetic analysis was performed and several characteristics of the hind limb, in particular some of the autopodium, resulted in the identification of new apomorphic traits for Ceratosauria and Abelisauridae. These features might prove to be useful for future phylogenetic analyses and may help to resolve the still confusing and debated internal relationships of abelisaurid theropods.
DOI: 10.6084/m9.figshare.21751141
title: Phylogeny of the Ordovician and Silurian members of the order Atrypida

description: Brachiopods belonging to order Atrypida originated in the Middle Ordovician and went extinct in the Late Devonian. Few cladistic studies have been undertaken for this group. Here we investigate their early evolution through Silurian time. We present a parsimony-based phylogenetic analysis of 41 characters and 70 genera representing all the early taxonomic groups within the order. The stratigraphical record of the fossil genera analysed strongly aligns with the phylogeny recovered from our parsimony analysis. Most currently recognized subfamilies and families may be identified within clades, except for the Atrypinae, Idiospirinae, and the Septatrypidae. This warrants subdivision of the former and redefinition of the latter two. The subfamily Atrypinae is redefined, and a new subfamily of the Atrypidae, the Protatrypinae, is split off. Tracing character evolution across the tree indicates that the calcified spiralia and a jugum or jugal processes characterize all members of the Atrypida, except the most basal clade, the Cyclospiridae, which lacks a calcified jugum. Ribs are a homoplasious character, occurring in numerous clades throughout the tree. Darriwillian through Sandbian ages represent times with rapid evolution when most new autapomorphies seen in the atrypides evolved. This interval is the first major part of the Great Ordovician Biodiversification Event (GOBE). Solid teeth, dorsal direction of spiralia, elaborate ornamentation, and frills evolved in the latest Katian into early Silurian time. Solid teeth seen in distantly related clades from latest Katian onwards may be an analogous feature. The Late Ordovician Mass Extinction (LOME) is indicated in the stratigraphical tree together with a possible event at the end of the Aeronian. The tree supports the long-held assumptions that the Plectatrypinae evolved from the Spirigerininae. It further suggests that the genus <i>Tuvaella</i> may be included with the Davidsonioidea. Likewise, the redefined Atrypinae is a sister group of the Lissatrypidae and a derived group in the phylogenetic tree.
DOI: 10.6084/m9.figshare.21763371
title: A nearly complete skeleton of a new eusphenodontian from the Upper Jurassic Morrison Formation, Wyoming, USA, provides insight into the evolution and diversity of Rhynchocephalia (Reptilia: Lepidosauria)

description: We describe a new, small-bodied rhynchocephalian reptile, <i>Opisthiamimus gregori</i> gen. et sp. nov., from the Upper Jurassic Morrison Formation of Wyoming, USA. Whereas many fossil rhynchocephalians are based on isolated incomplete jaws, the holotype of <i>O</i>. <i>gregori</i> includes most of the skull and postcranium and therefore represents one of the most complete specimens of Rhynchocephalia known from North America. We used micro-computed tomography to examine its skeletal anatomy in detail and to develop a three-dimensional reconstruction of the skull. The skull of <i>O. gregori</i> is similar to that of several non-neosphenodontian rhynchocephalians such as <i>Planocephalosaurus</i> (e.g. large orbits) and <i>Clevosaurus</i> (e.g. parietal parasagittal crests) yet exhibits a suite of other features related to the proal shearing mechanism that becomes increasingly elaborated among more phylogenetically nested taxa such as <i>Sphenodon</i> (e.g. lateral palatine tooth row parallels maxillary tooth row along its entire length, pyramidal dentary teeth with mesial shearing crests). The postcranial skeleton of <i>O. gregori</i> exhibits characteristics typical of a terrestrial rhynchocephalian. Our phylogenetic analyses use a substantially updated data set of 118 characters and 46 taxa, and both maximum parsimony and Bayesian frameworks. Results place <i>O</i>. <i>gregori</i> inside Eusphenodontia but outside Neosphenodontia, and therefore in a key position for contributing to character polarity for more deeply nested clades such as Clevosauridae, Sphenodontidae and Pleurosauridae. We also erect Leptorhynchia taxon nov., composed primarily of aquatically adapted taxa (e.g. <i>Pleurosaurus</i>, <i>Sapheosaurus</i>), which is supported by both cranial and postcranial characters. Because <i>O. gregori</i> is not particularly closely related to the other named Morrison rhynchocephalians (e.g. <i>Opisthias rarus</i>), it increases both the alpha and beta taxonomic diversities within the formation. Similarly, major differences in body size and inferred diet of the Morrison taxa imply considerable concomitant palaeoecological diversity just prior to a major global decline in rhynchocephalian diversity around the close of the Jurassic. http://zoobank.org/urn:lsid:zoobank.org:pub:888E055B-8AC1-4BD0-A37C-8CB192F79673
DOI: 10.6084/m9.figshare.20731082
title: A new aetiocetid (Cetacea, Mysticeti, Aetiocetidae) from the late Oligocene of Mexico

description: The aetiocetids are a well-known extinct taxon of Oligocene toothed mysticetes in the North Pacific. They display a high degree of diversity contrasting with that of other tooth-bearing mysticetes such as mammalodontids, llanocetids and <i>Coronodon</i> spp. The disparate developmental patterns (heterochrony) and origin of the first kelp forests in the North Pacific during the Eocene–Oligocene transition might explain such diversity. Aetiocetidae have been the focus of debate regarding the origin of baleen and filter-feeding in Mysticeti. The current interpretation of aetiocetid feeding strategies is based on the presence of teeth, unfused mandibular symphysis and lateral palatal foramina. However, our understating of their feeding apparatus function is limited, leaving associated structures like the zygomatic arch unnoticed. The present study describes a new fossil of a small-sized mysticete (∼3 m long), <i>Kaaucetus thesaurus</i> gen. et sp. nov., which belongs to Aetiocetidae. The protruded squamosal prominence and distinctive zygomatic process present in this new fossil highlight disparity in feeding morphology amongst aetiocetids. Moreover, the zygomatic arch complex and masticatory muscle system reconstruction are crucial to interpreting the likely capability of mastication (shearing motion) in aetiocetids and other toothed mysticetes. Lastly, the record of several aetiocetid genera in Mexico extends the geographical range of the group into the subtropical region. https://zoobank.org/urn:lsid:zoobank.org:pub:urn:lsid:zoobank.org:pub:26167623-8F9C-4C03-8CA2-911D93519031
DOI: 10.6084/m9.figshare.20731082.v1
title: A new aetiocetid (Cetacea, Mysticeti, Aetiocetidae) from the late Oligocene of Mexico

description: The aetiocetids are a well-known extinct taxon of Oligocene toothed mysticetes in the North Pacific. They display a high degree of diversity contrasting with that of other tooth-bearing mysticetes such as mammalodontids, llanocetids and <i>Coronodon</i> spp. The disparate developmental patterns (heterochrony) and origin of the first kelp forests in the North Pacific during the Eocene–Oligocene transition might explain such diversity. Aetiocetidae have been the focus of debate regarding the origin of baleen and filter-feeding in Mysticeti. The current interpretation of aetiocetid feeding strategies is based on the presence of teeth, unfused mandibular symphysis and lateral palatal foramina. However, our understating of their feeding apparatus function is limited, leaving associated structures like the zygomatic arch unnoticed. The present study describes a new fossil of a small-sized mysticete (∼3 m long), <i>Kaaucetus thesaurus</i> gen. et sp. nov., which belongs to Aetiocetidae. The protruded squamosal prominence and distinctive zygomatic process present in this new fossil highlight disparity in feeding morphology amongst aetiocetids. Moreover, the zygomatic arch complex and masticatory muscle system reconstruction are crucial to interpreting the likely capability of mastication (shearing motion) in aetiocetids and other toothed mysticetes. Lastly, the record of several aetiocetid genera in Mexico extends the geographical range of the group into the subtropical region. https://zoobank.org/urn:lsid:zoobank.org:pub:urn:lsid:zoobank.org:pub:26167623-8F9C-4C03-8CA2-911D93519031
DOI: 10.6084/m9.figshare.21308018
title: Description of <i>Acheronauta</i> gen. nov., a possible mandibulate from the Silurian Waukesha Lagerstätte, Wisconsin, USA

description: The Silurian Waukesha Lagerstätte of Wisconsin, USA, hosts a fauna of distinctive soft-bodied organisms, including a range of graptolites, worms, trilobites and uncommon arthropods, but otherwise lacks most of the shelly fauna typical of contemporaneous deposits. While several species have been described, much of the Waukesha biota remains understudied. Here, we examine numerous specimens of a previously unnamed and undescribed vermiform arthropod that bears a cephalic carapace, a suite of specialized head appendages, a long, segmented trunk, and a battery of small swimming appendages. The taxonomic and phylogenetic evaluations presented herein establish this taxon as a novel genus and species, <i>Acheronauta stimulapis</i> gen. et sp. nov., plausibly positioned within the basal mandibulates. Our phylogenetic analyses suggest that a new arthropod clade may be warranted, comprising <i>Acheronauta</i> gen. nov., <i>Captopodus</i>, and the thylacocephalans. https://zoobank.org/urn:lsid:zoobank.org:pub:B572831B-1A8A-4E4E-9258-34D91AA22A74nk
DOI: 10.6084/m9.figshare.21308018.v1
title: Description of <i>Acheronauta</i> gen. nov., a possible mandibulate from the Silurian Waukesha Lagerstätte, Wisconsin, USA

description: The Silurian Waukesha Lagerstätte of Wisconsin, USA, hosts a fauna of distinctive soft-bodied organisms, including a range of graptolites, worms, trilobites and uncommon arthropods, but otherwise lacks most of the shelly fauna typical of contemporaneous deposits. While several species have been described, much of the Waukesha biota remains understudied. Here, we examine numerous specimens of a previously unnamed and undescribed vermiform arthropod that bears a cephalic carapace, a suite of specialized head appendages, a long, segmented trunk, and a battery of small swimming appendages. The taxonomic and phylogenetic evaluations presented herein establish this taxon as a novel genus and species, <i>Acheronauta stimulapis</i> gen. et sp. nov., plausibly positioned within the basal mandibulates. Our phylogenetic analyses suggest that a new arthropod clade may be warranted, comprising <i>Acheronauta</i> gen. nov., <i>Captopodus</i>, and the thylacocephalans. https://zoobank.org/urn:lsid:zoobank.org:pub:B572831B-1A8A-4E4E-9258-34D91AA22A74nk
DOI: 10.6084/m9.figshare.20518458
title: New allotherian specimens from the Middle Jurassic Woodeaton Quarry (Oxfordshire) and implications for haramiyidan diversity and phylogeny

description: We report new allotherian tooth specimens from the Middle Jurassic White Limestone Formation at Woodeaton Quarry (Oxfordshire), United Kingdom. Two teeth are assigned to <i>Kermackodon</i> (=<i>Eleutherodon</i>) <i>oxfordensis</i>, a taxon whose original generic name (<i>Eleutherodon</i>) was preoccupied and is here assigned to <i>Kermackodon</i> to form a new binomial combination for the species name. <i>Butlerodon quadratus</i> gen. et sp. nov. (family Kermackodontidae), based on 13 cheek teeth and incisors, shows dental features intermediate between <i>K. oxfordensis</i> and the Late Triassic “haramiyidans” (<i>Haramiyavia</i> and <i>Thomasia</i>). <i>Woodeatonia parva</i> gen. et sp. nov. (family indeterminate), based on three teeth, is characterized by its small size. A second upper molar from a multituberculate is identified as <i>Hahnotherium</i> cf. <i>H. antiquum</i>, which possesses characters typical for multituberculates but distinctive from “haramiyidans”. The allotherian teeth from the Forest Marble Formation, previously assigned to the haramiyidans “<i>Eleutherodon</i>”, “<i>Millsodon</i>” and “<i>Kirtlingtonia</i>”, and the multituberculate <i>Kermackodon</i>, are reinterpreted as teeth from different upper or lower dental loci of the same haramiyidan species <i>K. oxfordensis</i>, which result in significant taxonomical modification of these allotherians (“haramiyidans” and multituberculates). Given that <i>Kermackodon</i> has been regarded as a transitional form between multituberculates and “haramiyidans”, these taxonomical modifications would affect interpretation of early evolution of allotherians. In a comparison of molars in known “haramiyidans”, we delve into their occlusal patterns and cusp homologies that have been controversial but pivotal for understanding evolution of allotherians. We further conduct the first phylogenetic analysis of haramiyidan species. The European Late Triassic species form the stem-ward taxa of “haramiyidans” and the Jurassic species from the United Kingdom are grouped with arboroharamiyids from the Yanliao Biota, China, and nested in “haramiyidans”. http://zoobank.org/urn:lsid:zoobank.org:pub:38F1FB5A-17A2-498F-B1FD-38D975548201 http://zoobank.org/urn:lsid:zoobank.org:act:FF5ADA10-C044-4541-ADA6-54448F17C673 http://zoobank.org/urn:lsid:zoobank.org:act:6E59071A-56DF-43D2-A140-2860465BFECA http://zoobank.org/urn:lsid:zoobank.org:act:CA2EE3CF-951C-450A-879D-2AE438F6BB2A http://zoobank.org/urn:lsid:zoobank.org:act:6B26D9C3-9FC3-4517-A1EF-51822067F970
DOI: 10.6084/m9.figshare.20518458.v1
title: New allotherian specimens from the Middle Jurassic Woodeaton Quarry (Oxfordshire) and implications for haramiyidan diversity and phylogeny

description: We report new allotherian tooth specimens from the Middle Jurassic White Limestone Formation at Woodeaton Quarry (Oxfordshire), United Kingdom. Two teeth are assigned to <i>Kermackodon</i> (=<i>Eleutherodon</i>) <i>oxfordensis</i>, a taxon whose original generic name (<i>Eleutherodon</i>) was preoccupied and is here assigned to <i>Kermackodon</i> to form a new binomial combination for the species name. <i>Butlerodon quadratus</i> gen. et sp. nov. (family Kermackodontidae), based on 13 cheek teeth and incisors, shows dental features intermediate between <i>K. oxfordensis</i> and the Late Triassic “haramiyidans” (<i>Haramiyavia</i> and <i>Thomasia</i>). <i>Woodeatonia parva</i> gen. et sp. nov. (family indeterminate), based on three teeth, is characterized by its small size. A second upper molar from a multituberculate is identified as <i>Hahnotherium</i> cf. <i>H. antiquum</i>, which possesses characters typical for multituberculates but distinctive from “haramiyidans”. The allotherian teeth from the Forest Marble Formation, previously assigned to the haramiyidans “<i>Eleutherodon</i>”, “<i>Millsodon</i>” and “<i>Kirtlingtonia</i>”, and the multituberculate <i>Kermackodon</i>, are reinterpreted as teeth from different upper or lower dental loci of the same haramiyidan species <i>K. oxfordensis</i>, which result in significant taxonomical modification of these allotherians (“haramiyidans” and multituberculates). Given that <i>Kermackodon</i> has been regarded as a transitional form between multituberculates and “haramiyidans”, these taxonomical modifications would affect interpretation of early evolution of allotherians. In a comparison of molars in known “haramiyidans”, we delve into their occlusal patterns and cusp homologies that have been controversial but pivotal for understanding evolution of allotherians. We further conduct the first phylogenetic analysis of haramiyidan species. The European Late Triassic species form the stem-ward taxa of “haramiyidans” and the Jurassic species from the United Kingdom are grouped with arboroharamiyids from the Yanliao Biota, China, and nested in “haramiyidans”. http://zoobank.org/urn:lsid:zoobank.org:pub:38F1FB5A-17A2-498F-B1FD-38D975548201 http://zoobank.org/urn:lsid:zoobank.org:act:FF5ADA10-C044-4541-ADA6-54448F17C673 http://zoobank.org/urn:lsid:zoobank.org:act:6E59071A-56DF-43D2-A140-2860465BFECA http://zoobank.org/urn:lsid:zoobank.org:act:CA2EE3CF-951C-450A-879D-2AE438F6BB2A http://zoobank.org/urn:lsid:zoobank.org:act:6B26D9C3-9FC3-4517-A1EF-51822067F970