An enigmatic lower jaw from the Lower Muschelkalk (Anisian, Middle Triassic) of Winterswijk provides insights into dental configuration, tooth replacement and histology DOI Creative Commons
Stephan N. F. Spiekman, Nicole Klein

Netherlands Journal of Geosciences – Geologie en Mijnbouw, Journal Year: 2021, Volume and Issue: 100

Published: Jan. 1, 2021

Abstract In the aftermath of Permo-Triassic mass extinction event, several reptile lineages radiated to form major components marine faunas during entire Mesozoic. The Lower Muschelkalk, which was deposited within a shallow inland sea in Germanic Basin Middle Triassic, is one most important regions for understanding early evolution Mesozoic reptiles. Here, we present new specimen from Muschelkalk Winterswijk Netherlands, comprising an isolated left dentary that morphologically distinct any well-known Triassic vertebrate. We provide detailed description jaw and teeth using histological micro-computed tomographic analyses. anterior are fang-like curved, whereas posterior wider triangular-shaped. Tooth implantation thecodont ankylosed base alveolus. Replacement developed directly lingual functional teeth, starting with formation resorption cavity on dorsal surface alveolar margin. replacement pattern cannot be observed detail but regular part each tooth being alternated empty can likely assigned Eosauropterygia based its morphology dental pattern, it remarkably similar maxillae referred enigmatic Lamprosauroides goepperti Poland. lacks enlarged, ‘alveolarised’ crypts corresponding lamina foramina (DLFs) configuration typical Sauropterygia, not omnipresent this clade. also exhibits loosely folded plicidentine at roots representing first identification feature Sauropterygia.

Language: Английский

New insights into the postcranial anatomy of Exaeretodon riograndensis (Eucynodontia: Traversodontidae): phylogenetic implications, body mass, and lifestyle DOI
Leonardo Kerber, G. Montoya, Lívia Roese‐Miron

et al.

Journal of Mammalian Evolution, Journal Year: 2025, Volume and Issue: 32(1)

Published: Jan. 24, 2025

Language: Английский

Citations

1
The redescription of Malerisaurus robinsonae (Archosauromorpha: Allokotosauria) from the Upper Triassic lower Maleri Formation, Pranhita‐Godavari Basin, India DOI
Saradee Sengupta, Martín D. Ezcurra, Saswati Bandyopadhyay

et al.

The Anatomical Record, Journal Year: 2024, Volume and Issue: 307(4), P. 1315 - 1365

Published: Jan. 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

Language: Английский

Citations

6
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 DOI Creative Commons
Stephan N. F. Spiekman, Martín D. Ezcurra, Adam Rytel

et al.

Swiss Journal of Palaeontology, Journal Year: 2024, Volume and Issue: 143(1)

Published: March 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.

Language: Английский

Citations

5
‘Birds’ of two feathers: Avicranium renestoi and the paraphyly of bird-headed reptiles (Diapsida: ‘Avicephala’) DOI Creative Commons
Valentin Buffa, Eberhard Frey,

J-Sébastien Steyer

et al.

Zoological Journal of the Linnean Society, Journal Year: 2024, Volume and Issue: unknown

Published: May 11, 2024

Abstract The anatomy of Late Triassic drepanosauromorphs is re-examined, with a focus on the previously published surface models holotype Avicranium renestoi from Norian North America. We comment cranial this taxon and propose new reconstruction skull mandible. Contrary to previous interpretations, entire rostrum most palate are not preserved in specimen. also suggest that some proposed plesiomorphic characters may result incomplete ossification due immaturity. These observations compiled into morphological phylogenetic dataset designed address monophyly ‘Avicephala’, group comprising Permian gliding reptiles Weigeltisauridae, chameleon-like Drepanosauromorpha. recover Weigeltisauridae as stem-saurian diapsids Drepanosauromorpha sister-group Trilophosauridae among archosauromorphs, thus implying paraphyly ‘Avicephala’. Drepanosauromorphs trilophosaurids recovered sister-taxa for first time, supported by several postcranial synapomorphies. This position reduces group’s ghost lineage now does necessarily cross Permian–Triassic boundary. However, much remains unknown early history drepanosauromorphs, evolution arboreality archosauromorph reptiles.

Language: Английский

Citations

5
Extreme neck elongation evolved despite strong developmental constraints in bizarre Triassic reptiles—implications for neck modularity in archosaurs DOI Creative Commons
Adam Rytel, Christine Böhmer, Stephan N. F. Spiekman

et al.

Royal Society Open Science, Journal Year: 2024, Volume and Issue: 11(5)

Published: May 1, 2024

The Triassic radiation of vertebrates saw the emergence modern vertebrate groups, as well numerous extinct animals exhibiting conspicuous, unique anatomical characteristics. Among these, members Tanystropheidae (Reptilia: Archosauromorpha) displayed cervical vertebral elongation to an extent unparalleled in any other vertebrate. Tanystropheids were exceptionally ecologically diverse and had a wide spatial temporal distribution. This may have been related their neck anatomy, yet its evolution functional properties remain poorly understood. We used geometric morphometrics capture intraspecific variation between vertebrae comprising column among early archosauromorphs, trace evolutionary history these animals. Our results show that series reptiles can be divided into modules corresponding those extant achieved through somite shift thoracic regions, without presacral count increase—contrary crown archosaurs. suggests peculiar developmental constraint strongly affected tanystropheids. data obtained just at base archosauromorph phylogenetic tree are crucial for further studies on modularity columns not only reptile groups but well.

Language: Английский

Citations

5
An annotated checklist of Australian Mesozoic tetrapods DOI Creative Commons
Stephen F. Poropat, Phil R. Bell, Lachlan J. Hart

et al.

Alcheringa An Australasian Journal of Palaeontology, Journal Year: 2023, Volume and Issue: 47(2), P. 129 - 205

Published: April 3, 2023

In 2020, the Australasian palaeontological association Palaeontologists (AAP) joined Australian government-supported National Species List (auNSL) initiative to compile first Fossil (auFNSL) for region. The goal is assemble comprehensive systematic data on all vertebrate, invertebrate and plant fossil taxa described date, present information both within a continuously updated open-access online framework, as series of primary reference articles in AAP's flagship journal Alcheringa. This paper spearheads these auFNSL Alcheringa publications with an annotated checklist Mesozoic tetrapods. Complete synonymy, type material, source locality, geological age bibliographical are provided 111 species formally named 2022. addition, chronostratigraphically arranged inventories documented tetrapod occurrences presented illustrations significant, exceptionally preserved and/or diagnostic specimens. most diverse order-level clades include temnospondyl amphibians (34 species), saurischian (13 species) ornithischian (12 dinosaurs (excluding ichnotaxa), plesiosaurian marine reptiles (11 species). However, numerous other groups collectively span earliest Triassic (earliest Induan) Late Cretaceous (late Maastrichtian) incorporate antecedents modern lineages, such chelonioid chelid turtles monotreme mammals. Although scarce comparison records from continents, Australia's assemblages globally important because they constitute higher-palaeolatitude faunas that evince terrestrial ecosystem evolution near ancient South Pole. pace research has also accelerated substantially over last 20 years, serves promote geoheritage asset scientific, cultural economic development. augments accessibility utility resources provides foundation ongoing exploration into unique natural history.Stephen F. Poropat [[email protected]], Western Organic Isotope Geochemistry Centre, School Earth Planetary Science, Curtin University, Bentley, Australia 6102, Australia, Age Dinosaurs Museum Natural History, Lot 1 Dinosaur Drive, Winton, Queensland 4735, Australia; Phil R. Bell [[email protected]], Palaeoscience Research Environmental Rural University New England, Armidale, Wales 2351, Lachlan J. Hart [[email protected]], Sustainability Science Biological, Sciences (BEES), Wales, Kensington, 2052, Institute, William Street, Sydney, 2010, Steven W. Salisbury [[email protected]] Biological Sciences, Queensland, Brisbane, 4072, Benjamin P. Kear [[email protected]] Evolution, Uppsala Norbyvägen 16, SE-752 36, Sweden.

Language: Английский

Citations

13
A new archosauriform species from the Panchet Formation of India and the diversification of Proterosuchidae after the end-Permian mass extinction DOI Creative Commons
Martín D. Ezcurra, Saswati Bandyopadhyay, Dhurjati Prasad Sengupta

et al.

Royal Society Open Science, Journal Year: 2023, Volume and Issue: 10(10)

Published: Oct. 1, 2023

Proterosuchidae represents the oldest substantial diversification of Archosauromorpha and plays a key role in understanding biotic recovery after end-Permian mass extinction. was long treated as wastebasket taxon, but recent revisions have reduced its taxonomic content to five valid species from latest Permian Russia earliest Triassic (Induan) South Africa China. In addition these occurrences, several isolated proterosuchid bones been reported Induan Panchet Formation India for over 150 years. Following re-study historical specimens newly collected material this unit, we erect new Samsarasuchus pamelae , which is represented by most presacral vertebral column. We also describe cf. cranial, girdle limb that are not referred . Phylogenetic analyses recovered within clade Chasmatosuchinae. The diversity substantially expanded here, with at least 11 nominal currently unnamed specimens, biogeographical range encompassing present-day Africa, China, Russia, India, Brazil, Uruguay Australia. This indicates broader taxonomic, phylogenetic biogeographic than previously thought aftermath

Language: Английский

Citations

13
A new stem saurian reptile from the late Permian of South Africa and insights into saurian evolution DOI Creative Commons
Ethan D. Mooney, Diane Scott,

Robert Raphael Reisz

et al.

Swiss Journal of Palaeontology, Journal Year: 2025, Volume and Issue: 144(1)

Published: Feb. 26, 2025

Abstract The evolutionary radiation of diapsid reptiles that includes all extant and most extinct is well-represented in the Mesozoic Cenozoic fossil records, however, earliest stages recorded Paleozoic Era are limited to comparatively few taxa. Consequently, origins Sauria, crown-group Diapsida, remains poorly understood phylogenetic positions known taxa along saurian stem controversial. Here, we describe Akkedops bremneri sp. et gen. nov., a new early late Permian from Karoo South Africa based on two skulls show famous aggregation "juvenile Youngina ” SAM-PK-K7710 also referrable it, thereby making this one best-known saurians. skull has short rostrum, open lower temporal bar, large contribution postfrontal upper fenestra, slender stapes, sliver-like supratemporal with distinct lateral flange suturing postorbital, lacks both postparietal tabular bones. saddle-shaped quadrate rather saurian-like being posteriorly emarginated tympanic crest unique medial flange. post cranial skeleton lizard-like notably shows hook-shaped fifth metatarsal thyroid fenestra. Phylogenetic analysis recovers as sister which especially surprising considering its small size slender, morphology prior split between apparently similar lepidosauromorphs many robust archosauromorph Our indicates capensis falls outside clade bremenri + Sauria does not appear form other “younginiform” reptiles. available evidence level complexity related evolution saurians origin occurred shadow amniotes.

Language: Английский

Citations

0
Triassic terrestrial tetrapod faunas of the Central European Basin, their stratigraphical distribution, and their palaeoenvironments DOI Creative Commons
Eudald Mujal, Hans‐Dieter Sues, R. Moreno

et al.

Earth-Science Reviews, Journal Year: 2025, Volume and Issue: unknown, P. 105085 - 105085

Published: March 1, 2025

Language: Английский

Citations

0
Morphology of the maxilla informs about the type of predation strategy in the evolution of Abelisauridae (Dinosauria: Theropoda) DOI Creative Commons

Enzo E. Seculi Pereyra,

Juan Vrdoljak, Martín D. Ezcurra

et al.

Scientific Reports, Journal Year: 2025, Volume and Issue: 15(1)

Published: March 6, 2025

Abelisauridae is a clade of theropods distinguished by short, ornamented skulls and strongly reduced forelimbs. They represented the most abundant predatory dinosaurs in Gondwana during Cretaceous. Bolstered biomechanical studies, morphology skull vertebral column abelisaurids, have led researchers to hypothesize that Late Cretaceous forms were "specialized hunters." Here, we use abelisaurid maxilla test inclusion Lower Spectrovenator within specialized hunter category. Additionally, analyze diversity disparity macroevolutionary context. We quantified maxillary shape 17 taxa using 2D geometric morphometrics analyzed different evolutionary scenarios trends with phylogenetic comparative methods. The results all analyses (phylogenetic ordination methods, Z, R2 comparison generalized least squares, model selection, estimated taxa-removal analysis) suggest specialization appeared Early Cretaceous, revealing abelisaurids can be considered specialist hunters. High levels morphological occurred shortly after Cenomanian-Turonian faunistic turnover, which involved drastic changes South American terrestrial faunal assemblages. Moreover, high rates change support shift ecological pressures or socio-sexual mechanisms, main drivers evolution rostrum. Our study invites more osteological elements under quantitative framework our comprehensively.

Language: Английский

Citations

0