A comprehensive phylogenetic analysis on early ornithischian evolution

Journal of Systematic Palaeontology, Год журнала: 2024, Номер 22(1)

Опубликована: Июнь 21, 2024

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

Язык: Английский

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The redescription of Malerisaurus robinsonae (Archosauromorpha: Allokotosauria) from the Upper Triassic lower Maleri Formation, Pranhita‐Godavari Basin, India

The Anatomical Record, Год журнала: 2024, Номер 307(4), С. 1315 - 1365

Опубликована: Янв. 26, 2024

Abstract Allokotosauria, a clade of non‐archosauriform archosauromorphs with broad diversity body plans, plays crucial role in better understanding the evolutionary history early diverging stem‐archosaurs. Here we provide detailed redescription Malerisaurus robinsonae , malerisaurine allokotosaur from middle Carnian—lowermost Norian lower Maleri Formation, Pranhita‐Godavari Basin, India. The new anatomical information available recently discovered and well‐preserved skeletons various allokotosaurs, such as A zendohsaurus madagaskarensis Shringasaurus indicus Puercosuchus traverorum ‐like taxa, their comparison enriches our anatomy this species. To reassess phylogenetic relationships revised its scorings included eight additional allokotosaurian species to already most comprehensive dataset focused on Permo‐Triassic archosauromorphs. We modified 70 for analysis recovered at base Malerisaurinae group earliest branch Azendohsauridae. Pamelaria dolichotrachela is found non‐malerisaurine azendohsaurid sister taxon + Azendohsaurus spp. clade. Trilophosaurid interrelationships are well resolved, Teraterpeton hrynewichorum Coelodontognathus ricovi Rutiotomodon tytthos successive earliest‐branching position Anisodontosaurus greeri Variodens inopinatus bolsters long ghost lineages Late Triassic trilophosaurid record. disparity tooth crown morphology shows that Allokotosauria disparate archosauromorph clade, exploring almost complete range basic morphologies. Trilophosaurids occupy an area dental morphospace unique among

Язык: Английский

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Cranial osteology and paleoneurology of Tarjadia ruthae: An erpetosuchid pseudosuchian from the Triassic Chañares Formation (late Ladinian‐?early Carnian) of Argentina

The Anatomical Record, Год журнала: 2024, Номер 307(4), С. 890 - 924

Опубликована: Янв. 23, 2024

Abstract Tarjadia ruthae is a quadrupedal terrestrial pseudosuchian from the Middle‐early Upper Triassic of Chañares Formation, La Rioja Province, Argentina. Originally, this species was identified as an indeterminate archosaur and later doswelliid archosauriform based on very fragmentary specimens characterized by ornamentation skull roof osteoderms. Additional (including skulls postcrania) recovered in last decade show that erpetosuchid, enigmatic group composed six registered Middle‐Upper continental units Tanzania, Germany, Scotland, North America, Brazil, Argentina Parringtonia gracilis Tanzania are best preserved more abundant species. Although monophyly Erpetosuchidae well supported, alternative high‐level positions within Archosauria have been suggested, such sister taxon to Crocodylomorpha, Aetosauria, or Ornithosuchidae. In order improve knowledge about erpetosuchids, we performed detailed description paleoneurological reconstruction , two articulated partial (CRILAR‐Pv 478 CRILAR‐Pv 495) other specimens. We analyzed stratigraphic geographic occurrence historical new provided emended diagnosis (the same for genus species, due monotypy) along with comparative cranial endocast. The robust, thick strongly ornamented roof, triangular dorsal view, concave lateral margins at mid‐length form abrupt widened posterior region. external nares smallest openings skull. antorbital fossa deeply excavated has small heart‐shaped fenestra both lobes pointing anteriorly. supratemporal fenestrae large rounded orbits, infratemporal L‐shaped extensive excavation jugal, quadratojugal quadrate. hemimandibles low, slightly dentigerous region convex region, conferring them S‐shaped profile view. mandibular elliptic, being twice longer than high. maxillary dentition restricted anterior mid rostrum. Since braincase partially damaged, surface brain could not be entirely reconstructed. As result, endocast anteroposteriorly elongated seemingly flat, cephalic flexure seems lower expected suchian. labyrinth wider high, semicircular canals remarkably straight, canal one.

Язык: Английский

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A redescription of Trachelosaurus fischeri from the Buntsandstein (Middle Triassic) of Bernburg, Germany: the first European Dinocephalosaurus-like marine reptile and its systematic implications for long-necked early archosauromorphs

Swiss Journal of Palaeontology, Год журнала: 2024, Номер 143(1)

Опубликована: Март 15, 2024

Abstract Some of the earliest members archosaur-lineage (i.e., non-archosauriform archosauromorphs) are characterised by an extremely elongated neck. Recent fossil discoveries from Guanling Formation (Middle Triassic) southern China have revealed a dramatic increase in known ecomorphological diversity these long-necked archosauromorphs, including fully marine and viviparous Dinocephalosaurus orientalis . These recent merit reinvestigation enigmatic Triassic diapsid fossils contemporaneous European deposits housed historical collections. Here, we provide redescription Trachelosaurus fischeri , represented single, disarticulated specimen first described 1918. Due to its unique morphology, which includes short, bifurcating cervical ribs, high presacral vertebral count, this taxon has been referred either as “protorosaurian” archosauromorph or sauropterygian. Our revision clearly shows that represents unambiguous -like outside Formation. finding important systematic implications. Trachelosauridae Abel, 1919 senior synonym for recently identified Dinocephalosauridae Spiekman, Fraser Scheyer, 2021. Based on our phylogenetic analyses, employ two extensive datasets, also corroborate previous findings tanystropheids trachelosaurids represent families within larger monophyletic group among non-crocopodan is here named Tanysauria (clade nov.). minimally composed Pectodens zhenyuensis Austronaga minuta but one analyses found probably taxonomically broader clade may include Gracilicollum latens Fuyuansaurus acutirostris considerably expands spatial temporal range Anisian Central Basin. add growing evidence presence diverse reptiles during Middle Tanysauria. possess flipper-like limbs, counts, elongate necks, thus superficially resembling Jurassic Cretaceous plesiosaurs some regards.

Язык: Английский

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A new small-sized predatory pseudosuchian archosaur from the Middle-Late Triassic of Southern Brazil

Scientific Reports, Год журнала: 2024, Номер 14(1)

Опубликована: Июнь 20, 2024

Abstract Before the rise of dinosaurs and pterosaurs, pseudosuchians—reptiles from crocodilian lineage—dominated Triassic land ecosystems. This lineage diversified into several less inclusive clades, resulting in a wide ecomorphological diversity during Middle Late Triassic. Some giant pseudosuchians occupied top trophic webs, while others developed extensive bony armor as defense mechanism, which later evolved convergence avemetatarsalian lineage. On other hand, there were groups like Gracilisuchidae, was composed carnivorous forms with lightweight build than 1 m length. The fossil record gracilisuchids is geographically restricted to China Argentina, one ambiguous Brazil. In present study, first unambiguous gracilisuchid Brazil described. Parvosuchus aurelioi gen. et sp. nov. comes Dinodontosaurus Assemblage Zone Santa Maria Formation, associated Ladinian-Carnian boundary. Composed complete cranium, vertebrae, pelvic girdle hindlimbs, new species nests Gracilisuchus stipanicicorum Maehary bonapartei phylogenetic analysis. Its discovery fills taxonomic gap Brazilian pseudosuchian fauna reveals smallest known member this clade Zone, highlighting moment that preceded dawn dinosaurs.

Язык: Английский

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Mandibular anatomy of a new specimen of a prozostrodontian cynodont (Eucynodontia: Probainognathia) from the Upper Triassic of Brazil

The Science of Nature, Год журнала: 2025, Номер 112(1)

Опубликована: Янв. 14, 2025

Язык: Английский

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Accounting for sampling heterogeneity suggests a low paleolatitude origin for dinosaurs

Current Biology, Год журнала: 2025, Номер unknown

Опубликована: Янв. 1, 2025

Dinosaurs dominated Mesozoic terrestrial ecosystems for ∼160 million years, but their biogeographic origin remains poorly understood. The earliest unequivocal dinosaur fossils appear in the Carnian (∼230 Ma) of southern South America and Africa, leading most authors to propose southwestern Gondwana as likely center origin. However, high taxonomic morphological diversity these assemblages suggests a more ancient evolutionary history that is currently unsampled. Phylogenetic uncertainty at base Dinosauria, combined with subsequent appearance dinosaurs throughout Laurasia early history, further complicates this picture. Here, we estimate distribution archosaurian relatives under phylogenetic maximum likelihood framework, testing alternative topological arrangements incorporating potential abiotic barriers dispersal into our models. For first time, include spatiotemporal sampling heterogeneity models, which frequently supports low-latitude Gondwanan dinosaurs. These results are best supported when silesaurids constrained early-diverging ornithischians, because topology accounts otherwise substantial ornithischian ghost lineage, explaining group's absence from fossil record prior Early Jurassic. Our suggest archosaur radiation also took place within following end-Permian extinction before lineages dispersed across Pangaea ecologically climatically distinct provinces during Late Triassic. vertebrates under-sampled low paleolatitudes, findings heterogeneous has hitherto obscured true paleobiogeographic kin.

Язык: Английский

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Triassic pterosaur precursors of Brazil: catalog, evolutionary context, and a new hypothesis for phylogenetic relationships of Pterosauromorpha

Anais da Academia Brasileira de Ciências, Год журнала: 2025, Номер 97(suppl 1)

Опубликована: Янв. 1, 2025

Abstract Pterosaurs, remarkable for their extensive evolutionary history and role as the first vertebrates to achieve active flight, have long intrigued paleontologists public alike. Spanning over 150 million years vanishing at end of Mesozoic Era, pterosaurs represent a major radiation within terrestrial ecosystems. Despite prominence, origins remained complex puzzle in paleontology 200 years. We present comprehensive catalog pterosaur precursors specimens from Upper Triassic Candelária Sequence Santa Maria Supersequence southern Brazil discuss significance understanding pterosauromorph Pterosauria. Additionally, we carried out phylogenetic analysis investigate hypothesis that lagerpetids are closely related pterosaurs, incorporating new data into most dataset dinosauromorphs. Our results support pterosauromorphs, offering insights relationships between non-pterosaur pterosauromorphs better known volant relatives. This study highlights importance detailed anatomical analyses resolving underscores value fossil record early evolution pterosauromorphs.

Язык: Английский

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European origins of Squamata supported by biogeographic analysis of fossil-tip-dated phylogenies using paleocontinental plate-tectonic models

Comptes Rendus Palevol, Год журнала: 2025, Номер 24(9)

Опубликована: Март 25, 2025

Язык: Английский

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A saurischian (Archosauria, Dinosauria) ilium from the Upper Triassic of southern Brazil and the rise of Herrerasauria

The Anatomical Record, Год журнала: 2023, Номер 307(4), С. 1011 - 1024

Опубликована: Ноя. 16, 2023

Abstract The Carnian (Upper Triassic) rocks of the Candelária Sequence present a rich record dinosaurs, including some oldest known dinosaurs worldwide. In this contribution we describe first unequivocal dinosaur from Pivetta site, located in Restinga Sêca municipality, Southern Brazil. specimen CAPPA/UFSM 0373 is an isolated but well‐preserved left ilium. A thorough examination specimen's anatomy and phylogenetic analysis provides evidence that belongs to Herrerasauria. We were able identify several similarities with potential non‐herrerasaurid herrerasaurians (e.g., Tawa hallae , “ Caseosaurus crosbyensis ”), which previously only North American deposits. contrast, herrerasaurids Herrerasaurus ischigualastensis ) are almost exclusively South America. Our results support nesting as early‐diverging herrerasaurian. Furthermore, potentially herrerasaurian unambiguous beds, suggesting hidden diversity Sequence, can be revealed even by fragmentary specimens.

Язык: Английский

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