cometadata/datacite-titles-descriptions-related-identifiers huggingface dataset:
DOI: 10.6084/m9.figshare.26228427
title: <i>Comptonatus chasei</i>, a new iguanodontian dinosaur from the Lower Cretaceous Wessex Formation of the Isle of Wight, southern England

description: A new iguanodontian dinosaur, <i>Comptonatus chasei</i> gen. et sp. nov., is described from the Lower Cretaceous Wessex Formation of the Isle of Wight. These strata provide an important record of a critical time in the development of iguanodontian diversity. The specimen, which is described here for the first time, was found and excavated in 2013 and represents the most complete iguanodontian skeleton discovered in the Wealden Group for a century. A new taxon is diagnosed by several autapomorphies found in the neurocranium, teeth, coracoid and other parts of the body, together with a unique suite of characters. These include a dentary with a straight ventral border, and a markedly expanded prepubic blade. These features set it apart from the sympatric <i>Mantellisaurus atherfieldensis</i>, <i>Brighstoneus simmondsi</i> and <i>Iguanodon</i> cf. <i>bernissartensis</i>, increasing the known diversity of this clade in the Barremian–early Aptian of England. http://zoobank.org/urn:lsid:zoobank.org:pub:2F3125A5-BDEF-4835-8829-92104752A86F
DOI: 10.6084/m9.figshare.26312272
title: A new radiodont from the lower Cambrian (Series 2 Stage 3) Chengjiang Lagerstätte, South China informs the evolution of feeding structures in radiodonts

description: Radiodonts, a diverse clade of early Palaeozoic stem-group euarthropods, have provided critical information for understanding the evolution of this phylum, and were important constituents of marine ecosystems at this time. The well-known Chengjiang Lagerstätte (Cambrian Stage 3, <i>c</i>. 518 Ma) has yielded the highest known diversity of radiodonts of any Cambrian Konservat-Lagerstätten, and represents a crucial deposit for radiodont research. One important but generally overlooked Chengjiang radiodont taxon, previously identified as <i>Anomalocaris</i> sp. or Radiodont C, is herein designated as the type species of a new monotypic genus, <i>Shucaris ankylosskelos</i> gen. et sp. nov., based on dozens of specimens. <i>Shucaris</i> is distinctive for its combination of several characters, including the presence of two pairs of endites on its proximal-most claw podomere, posteriorly inward curved endites on claw podomeres 2–6, and, most strikingly, the coexistence of gnathobase-like structures and an oral cone. New material of <i>Ramskoeldia consimilis</i> records the first known oral cone in this species, confirming that oral cones and gnathobase-like structures co-occur in multiple radiodont taxa. Phylogenetic analyses retrieve <i>Shucaris</i> as either an early diverging member of Anomalocarididae or as sister to the clade Anomalocarididae + Amplectobeluidae. Moreover, our phylogenetic analyses also support the divergence between hurdiid and non-hurdiid radiodonts. https://zoobank.org/urn:lsid:zoobank.org:pub:6989C81B-06B2-4AED-8297-3B200A6F8D69
DOI: 10.6084/m9.figshare.26325429
title: A new genus of metriorhynchid crocodylomorph from the Lower Cretaceous of Germany

description: Here we describe a new genus and species of metriorhynchid crocodylomorph, <i>Enalioetes schroederi</i> gen. et sp. nov., from the lower Valanginian Stadthagen Formation (Lower Cretaceous) of north-western Germany. <i>Enalioetes schroederi</i> is the most complete and well-preserved Cretaceous metriorhynchid skull known to date, preserving most of the cranium and mandible, the atlas-axis complex and the first postaxial cervical vertebra. The specimen was previously attributed to the coeval enigmatic metriorhynchid <i>Enaliosuchus</i> (a <i>nomen dubium</i>) and, more recently, to <i>Cricosaurus</i>. Although the specific epithet <i>schroederi</i> has been used frequently in the literature, it has never been formally established. Herein, we demonstrate that the new taxon is distinct from all known metriorhynchids by a unique combination of characters including several autapomorphies such as: the lack of bulbous dorsolateral expansion in the posterior nasal cavity; mediolateral distance between the orbital canals being approximately 1.5 times the diameter of the orbital canals; lacrimal with dorsoventrally deep anterior process ventral to the preorbital fossa being equal to or greater than the depth of the jugal anterior process and the anterodorsal process of the lacrimal; and ascending processes at atlas intercentrum extending far dorsally to level of neural canal. <i>Enalioetes schroederi</i> contributes to the sparse global record of Cretaceous metriorhynchids and represents one of the stratigraphically youngest occurrences of the group. It can thus help to enhance our understanding of the metriorhynchid diversity during the Cretaceous Period. http://zoobank.org/urn:lsid:zoobank.org:pub:5139021C-8E09-4912-BF22-9DDF14A4C895
DOI: 10.6084/m9.figshare.26778096
title: A new platanistoid (Odontoceti: Squalodelphinidae) from the Early Miocene of Japan

description: Extant Ganges and Indus river dolphins are endangered species, but their relatives were more diverse in the past. The family Squalodelphinidae is a group of Miocene relatives of Ganges and Indus river dolphins. Our knowledge of squalodelphinids increased slowly in the nineteenth century and has expanded dramatically since the 2010s. Italy, Switzerland, eastern USA, Argentina, and Peru are fossil localities of named and well-preserved squalodelphinid fossils. Squalodelphinids are also known from New Zealand, Germany and Venezuela. However, only two specimens of this family have been reported from the North Pacific, in Washington State, USA, and Japan. Here, a new fossil dolphin (including the skull, right and left periotics and bullae, malleus, incus, hyoid bones and ribs) from the Haze Formation, Ichishi Group, Early Miocene (18.7–18.5 Ma) of Mie Prefecture, Japan is named as the new genus and species <i>Miodelphinus miensis.</i> Phylogenetic analysis places <i>Miodelphinus miensis</i> among squalodelphinids. The periotic of <i>Miodelphinus miensis</i> shows a large, posteriorly widened, ventrally opening, funnel-like articular depression between the posterior and articular processes of the periotic. <i>Miodelphinus miensis</i> contributes to expanding our knowledge of squalodelphinid diversity. Squalodelphinids were distributed widely not only in the Atlantic but also the South and North Pacific by the Early Miocene. This suggests that the family had a chronologically deeper origin such as the beginning of the Early Miocene or older. https://zoobank.org/urn:lsid:zoobank.org:pub:DB7DDDE2-1095-4815-975B-8E1686559C2E
DOI: 10.6084/m9.figshare.26778096.v1
title: A new platanistoid (Odontoceti: Squalodelphinidae) from the Early Miocene of Japan

description: Extant Ganges and Indus river dolphins are endangered species, but their relatives were more diverse in the past. The family Squalodelphinidae is a group of Miocene relatives of Ganges and Indus river dolphins. Our knowledge of squalodelphinids increased slowly in the nineteenth century and has expanded dramatically since the 2010s. Italy, Switzerland, eastern USA, Argentina, and Peru are fossil localities of named and well-preserved squalodelphinid fossils. Squalodelphinids are also known from New Zealand, Germany and Venezuela. However, only two specimens of this family have been reported from the North Pacific, in Washington State, USA, and Japan. Here, a new fossil dolphin (including the skull, right and left periotics and bullae, malleus, incus, hyoid bones and ribs) from the Haze Formation, Ichishi Group, Early Miocene (18.7–18.5 Ma) of Mie Prefecture, Japan is named as the new genus and species <i>Miodelphinus miensis.</i> Phylogenetic analysis places <i>Miodelphinus miensis</i> among squalodelphinids. The periotic of <i>Miodelphinus miensis</i> shows a large, posteriorly widened, ventrally opening, funnel-like articular depression between the posterior and articular processes of the periotic. <i>Miodelphinus miensis</i> contributes to expanding our knowledge of squalodelphinid diversity. Squalodelphinids were distributed widely not only in the Atlantic but also the South and North Pacific by the Early Miocene. This suggests that the family had a chronologically deeper origin such as the beginning of the Early Miocene or older. https://zoobank.org/urn:lsid:zoobank.org:pub:DB7DDDE2-1095-4815-975B-8E1686559C2E
DOI: 10.6084/m9.figshare.27901558
title: Phylogenetic affinities and evolution of the Early Cambrian hexangulaconulariids

description: The abrupt appearance of abundant small shelly fossils (SSFs) near the base of the Cambrian System signals a key event in the evolutionary history of the Kingdom Metazoa. Among the probable cnidarian taxa, the SSF family Hexangulaconulariidae (Terreneuvian Series) is characterized by a fan-shaped, biradially symmetrical periderm having distinct apical and abapical portions, the latter of which bears multiple faces. Documented herein are three new hexangulaconulariid specimens from Cambrian Stage 2 on the Yangtze Platform (South China). The new specimens exhibit nine or 11 faces on each of the two sides of the abapical portion. Results of a Bayesian analysis of the phylogenetic relationships among hexangulaconulariids, carinachitids, conulariids, olivooids, and extant cnidarian genera indicate that hexangulaconulariids constitute a well-defined clade within a polytomic, stem-group Medusozoa that also includes carinachitids, conulariids and olivooids. The evolution of hexangulaconulariids featured multiple instances of increase in the total number of faces, modification of the morphology of the interfacial boundaries, and increase in the total size of the periderm. Increase in the number of faces appears to have been achieved in part by the transformation of a single ancestral face into three faces, through the development of a longitudinal furrow or ridge along each of the two adapically converging loci of inflection points (angular bends) of the prominent transverse ribs of the ancestral face.
DOI: 10.6084/m9.figshare.27161795
title: The anatomy and taxonomy of the North African Early Miocene crocodylian ‘<i>Tomistoma</i>’ <i>dowsoni</i> and the phylogenetic relationships of gavialoids

description: For decades, the interrelationships of the extant crocodylians <i>Gavialis gangeticus</i> and <i>Tomistoma schlegelii</i> have been debated, with only recent morphological phylogenetic analyses recovering the sister-taxon relationship between these two gavialoid species that has long been apparent in topologies based on molecular data. Several extinct species from the Mediterranean region are currently assigned to <i>Tomistoma</i>; however, their phylogenetic placement is labile, and often they do not form a clade with <i>Tomistoma schlegelii</i>. Here, we present a revision of <i>Tomistoma dowsoni</i> from the Early Miocene of Egypt and Libya, based on the type specimen (a partial snout and mandible) and referred material, including a nearly complete skull. These specimens show no notable anatomical differences and diagnostic features include: (1) a heart-shaped naris; (2) a prefrontal and lacrimal that are equidimensional in anteroposterior length; and (3) a prominent posterior process of the supraoccipital with a convex posterior margin. Maximum parsimony analysis, under both equal and extended implied weighting, recovers <i>Tomistoma dowsoni</i> as a phylogenetically nested gavialine, distantly related to <i>Tomistoma schlegelii</i> and other Mediterranean species currently referred to <i>Tomistoma</i>. Instead, <i>Tomistoma dowsoni</i> forms a sister-taxon relationship with <i>Eogavialis andrewsi</i>, from the Late Miocene of Kenya. Given that this clade does not consistently cluster with the type species of <i>Eogavialis</i>, and that <i>Tomistoma dowsoni</i> is diagnostic and clearly not referrable to <i>Tomistoma</i>, we herein erect the genus <i>Sutekhsuchus</i>, with the new combination <i>Sutekhsuchus dowsoni</i>. Our phylogenetic analyses recover the European Miocene gavialoids in a monophyletic group with the North American <i>Thecachampsa</i>, forming a clade of early-diverging gavialines that underwent transoceanic dispersal. We also recover a monophyletic group of thoracosaurs, comprising <i>Eothoracosaurus</i>, <i>Portugalosuchus</i>, and <i>Thoracosaurus</i>, which is expanded to include other Late Cretaceous–Early Paleogene European, North American, and North African species under extended implied weighting. https://zoobank.org/urn:lsid:zoobank.org:pub:2DE71417-8088-4749-8672-72E4A40C0B39
DOI: 10.6084/m9.figshare.27225408
title: Cranial anatomy of <i>Bagualia alba</i> (Dinosauria, Eusauropoda) from the Early Jurassic of Patagonia and the implications for sauropod cranial evolution

description: Sauropods are the largest terrestrial vertebrates ever known. During their evolution, they underwent numerous morphological changes, some of which occurred at the end of the Early Jurassic. However, current knowledge of Early Jurassic dinosaurs is scarce, especially cranial information. Here we describe the skull of the basal eusauropod <i>Bagualia alba</i> from the Cañadón Asfalto Formation (Toarcian; Early Jurassic) of Patagonia, Argentina, which represents the most complete eusauropod skull from the late Early Jurassic worldwide. The osteological description and phylogenetic relationships of <i>Bagualia</i> allowed us to determine the acquisition of the common cranial bauplan of eusauropods at the end of the Early Jurassic: a tall and robust rostrum with great retraction of the external nares; a deep narial fossa; a reduced antorbital fenestra; verticalization of the lacrimal; prefrontal without an anterior process; anteroposterior shortening of the frontal; a supratemporal fenestra visible laterally; a robust braincase; ‘U’-shaped jaws in dorsal view; reduction in the number of teeth in the dentary; teeth with crown to crown occlusion; development of lateral plates in the premaxilla and maxilla; and a dorsoventral expansion of the dentary symphysis. These cranial characteristics were recently suggested to be related to a change in the diet of the sauropods toward mainly hard vegetation. In this context, <i>Bagualia</i> contributes to filling a gap in cranial evolution between the gracile skulls of Sauropodiformes and the highly robust skulls widely represented in Middle Jurassic taxa.
DOI: 10.6084/m9.figshare.26076646
title: A comprehensive phylogenetic analysis on early ornithischian evolution

description: Resolving the evolutionary relationships of early diverging (‘basal’) ornithischian dinosaurs is a challenging topic in palaeontology, with multiple competing hypotheses on the phylogenetic relationships of heterodontosaurids, ‘hypsilophodontids’, and other early-diverging forms. These hypotheses cannot be directly compared because they are derived from differently constructed datasets (i.e. distinct samples of taxa and characters). This study aims to address these issues by revising and combining the distinct datasets into a single analysis in order to create the most comprehensive dataset for the investigation of the phylogenetic relationships of early-diverging ornithischians. A diphyletic model of <i>Dinosauria</i> is supported, with silesaurs nesting as members of <i>Ornithischia. Heterodontosauridae</i> is resolved as a clade of non-genasaurian ornithischians, rejecting a potential relationship with <i>Marginocephalia</i>. ‘Hypsilophodontid’ taxa span the neornithischian and ornithopod stem, with <i>Thescelosauridae</i> as the sister taxon to Cerapoda. A more restricted <i>Ornithopoda</i> is composed of five main clades: <i>Hypsilophodontidae</i>, <i>Rhabdodontomorpha</i>, <i>Elasmaria</i>, <i>Dryosauridae</i> and <i>Ankylopollexia. Hypsilophodontidae</i> is a valid clade, reduced to two European Barremian taxa. <i>Rhabdodontomorpha</i> does not contain <i>Muttaburrasaurus</i> as originally proposed, but instead expands to include a North American clade formed by <i>Convolosaurus</i>, <i>Iani</i> and <i>Tenontosaurus. Elasmaria</i> contains all non-dryomorph Gondwanan ornithopods, with its members possessing multiple distinct body plans. New results and comparison with previous studies suggest that some members of <i>Dryosauridae</i> are not ‘true dryosaurids’ but various early euiguanodontians that may be more closely related to either <i>Elasmaria</i> or <i>Ankylopollexia</i>. Results group most ‘hypsilophodontids’ in larger clades, significantly reducing the number and extension of ghost lineages throughout all of <i>Neornithischia</i>. These clades also show a degree of endemism, with different lineages present at different continents in the Late Cretaceous. This new phylogenetic analysis unifying previous works will provide a framework for future studies on origins and relations of early diverging ornithischians, and attempting to find stability among the different competing hypotheses.
DOI: 10.6084/m9.figshare.26335970
title: The phylogeny of Macraucheniidae (Mammalia, Panperissodactyla, Litopterna) at the genus level

description: Macraucheniidae is one of the most diverse families of South American native ungulates. In the last decade, Macraucheniidae systematics has been the focus of several studies with the aim of enhancing understanding of the diversity and phylogenetic relationships of the group. This study proposes a new phylogenetic hypothesis for the Macraucheniidae based on new characters and new outgroups. We included eight non-macraucheniid taxa as outgroups (three Didolodontidae, one Protolipternidae, two Proterotheriidae, and two Adianthidae); additionally, we included the 16 genera that are currently accepted as belonging to Macraucheniidae based on other cladistic studies. The matrix used in the cladistic analysis comprised 24 taxa and 71 characters. The genus <i>Polymorphis</i> was recovered as the sister taxon of a clade composed of Proterotheriidae + Adianthidae + Macraucheniidae, not as a macraucheniid. Disregarding <i>Polymorphis</i>, all other genera attributed to the Macraucheniidae were recovered in a monophyletic group. We found support for two macraucheniid clades, one formed by Cramaucheniinae (including <i>Theosodon</i>) and the other by all Macraucheniinae with the inclusion of <i>Llullataruca</i>. The late Pliocene <i>Windhausenia</i> was recovered as the sister group of ‘Quaternary macraucheniids’, with <i>Xenorhinotherium</i> as the sister group of <i>Macraucheniopsis</i> + <i>Macrauchenia</i>. Based on this topology, <i>Polymorphis</i> must be considered as family <i>incertae sedis</i>. Our findings have significant implications for understanding the origin and diversification of Macraucheniidae, altering the temporal range of the family to the late Oligocene–Late Pleistocene/Holocene. Additionally, <i>Llullataruca</i> becomes the oldest recorded member of the Macraucheniinae. The evolution of the nasal retraction in the iconic species <i>Macrauchenia patachonica</i> has consistently been interpreted through the lens of the phyletic gradualism model, with <i>Theosodon</i> as the intermediate form between species with totally reduced or absent nasals, and those basal forms with well-developed nasals and terminal nostrils. However, the monophyly of Cramaucheniinae suggests a rapid morphological shift among Macraucheniinae, which fits with a punctuated equilibrium evolutionary model.
DOI: 10.6084/m9.figshare.26076646.v1
title: A comprehensive phylogenetic analysis on early ornithischian evolution

description: Resolving the evolutionary relationships of early diverging (‘basal’) ornithischian dinosaurs is a challenging topic in palaeontology, with multiple competing hypotheses on the phylogenetic relationships of heterodontosaurids, ‘hypsilophodontids’, and other early-diverging forms. These hypotheses cannot be directly compared because they are derived from differently constructed datasets (i.e. distinct samples of taxa and characters). This study aims to address these issues by revising and combining the distinct datasets into a single analysis in order to create the most comprehensive dataset for the investigation of the phylogenetic relationships of early-diverging ornithischians. A diphyletic model of <i>Dinosauria</i> is supported, with silesaurs nesting as members of <i>Ornithischia. Heterodontosauridae</i> is resolved as a clade of non-genasaurian ornithischians, rejecting a potential relationship with <i>Marginocephalia</i>. ‘Hypsilophodontid’ taxa span the neornithischian and ornithopod stem, with <i>Thescelosauridae</i> as the sister taxon to Cerapoda. A more restricted <i>Ornithopoda</i> is composed of five main clades: <i>Hypsilophodontidae</i>, <i>Rhabdodontomorpha</i>, <i>Elasmaria</i>, <i>Dryosauridae</i> and <i>Ankylopollexia. Hypsilophodontidae</i> is a valid clade, reduced to two European Barremian taxa. <i>Rhabdodontomorpha</i> does not contain <i>Muttaburrasaurus</i> as originally proposed, but instead expands to include a North American clade formed by <i>Convolosaurus</i>, <i>Iani</i> and <i>Tenontosaurus. Elasmaria</i> contains all non-dryomorph Gondwanan ornithopods, with its members possessing multiple distinct body plans. New results and comparison with previous studies suggest that some members of <i>Dryosauridae</i> are not ‘true dryosaurids’ but various early euiguanodontians that may be more closely related to either <i>Elasmaria</i> or <i>Ankylopollexia</i>. Results group most ‘hypsilophodontids’ in larger clades, significantly reducing the number and extension of ghost lineages throughout all of <i>Neornithischia</i>. These clades also show a degree of endemism, with different lineages present at different continents in the Late Cretaceous. This new phylogenetic analysis unifying previous works will provide a framework for future studies on origins and relations of early diverging ornithischians, and attempting to find stability among the different competing hypotheses.