Unexpected new lizard from the Late Cretaceous of southern South America sheds light on Gondwanan squamate diversity

Martinelli, Agustín G.; Agnolín, Federico; Ezcurra, Martín D.

doi:10.22179/revmacn.23.716

Cited by 5 publications

(2 citation statements)

References 81 publications

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“…The Bajo de la Carpa Formation has yielded fossils that collectively represent a diverse and important paleobiota [30,32,[36][37][38][39][40][41][42][43][44][45][46][47][48][49][50][51][52][53][54][55]. Vertebrate remains are abundant and often well-preserved, and include those of snakes (Dinilysia patagonica), lizards (Paleochelco occultato), turtles (Lomalatachelys neuquina), crocodyliforms (Notosuchus terrestris, Comahuesuchus brachybuccalis,…”

Section: Associated Biotamentioning

confidence: 99%

Diuqin lechiguanae gen. et sp. nov., a new unenlagiine (Theropoda: Paraves) from the Bajo de la Carpa Formation (Neuquén Group, Upper Cretaceous) of Neuquén Province, Patagonia, Argentina

Porfiri,

Baiano,

dos Santos

et al. 2024

BMC Ecol Evo

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Background Unenlagiine paravians are among the most relevant Gondwanan theropod dinosaur clades for understanding the origin of birds, yet their fossil record remains incomplete, with most taxa being represented by fragmentary material and/or separated by lengthy temporal gaps, frustrating attempts to characterize unenlagiine evolution. Results and conclusions Here we describe Diuqin lechiguanae gen. et sp. nov., a new unenlagiine taxon from the Upper Cretaceous (Santonian) Bajo de la Carpa Formation of the Neuquén Basin of Neuquén Province in northern Patagonia, Argentina that fills a substantial stratigraphic gap in the fossil record of these theropods. Although known only from a very incomplete postcranial skeleton, the preserved bones of Diuqin differ from corresponding elements in other unenlagiines, justifying the erection of the new taxon. Moreover, in several morphological aspects, the humerus of Diuqin appears intermediate between those of geologically older unenlagiines from the Neuquén Basin (e.g., Unenlagia spp. from the Turonian–Coniacian Portezuelo Formation) and that of the stratigraphically younger, larger-bodied Austroraptor cabazai from the Campanian–Maastrichtian Allen Formation. Consequently, the morphology of the new taxon appears to indicate a transitional stage in unenlagiine evolution. Phylogenetic analysis recovers Diuqin as a paravian with multiple plausible systematic positions, but the strongest affinity is with Unenlagiinae. The humerus of the new form exhibits subcircular punctures near its distal end that are interpreted as feeding traces most likely left by a conical-toothed crocodyliform, mammal, or theropod, the latter potentially corresponding to a megaraptorid or another unenlagiine individual. Thus, in addition to filling important morphological and temporal gaps in unenlagiine evolutionary history, the new taxon also offers information relating to the paleoecology of these theropods.

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Section: Associated Biotamentioning

confidence: 99%

Diuqin lechiguanae gen. et sp. nov., a new unenlagiine (Theropoda: Paraves) from the Bajo de la Carpa Formation (Neuquén Group, Upper Cretaceous) of Neuquén Province, Patagonia, Argentina

Porfiri,

Baiano,

dos Santos

et al. 2024

BMC Ecol Evo

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“…Their members are characterized by labiolingually expanded upper and lower postcanine teeth with an occlusal basin, which typically vary in morphology among different species (Crompton, 1972; Hendrickx et al, 2019; Kemp, 2005; Liu & Abdala, 2014; Martinelli, 2010). Such dentition coupled with deep dentaries, and highly developed zygomatic arches and parietal crest (all highlighting broad areas for muscle attachment related to mastication), allowed researchers to infer a herbivorous/omnivorous diet to this group (e.g., Crompton, 1972; Goñi & Abdala, 1988; Goñi & Goin, 1987, 1988; Hendrickx et al, 2020; Kubo et al, 2017; Liu & Abdala, 2014; Martinelli & Soares, 2016).…”

Section: Introductionmentioning

confidence: 99%

Old fossil findings in the Upper Triassic rocks of southern Brazil improve diversity of traversodontid cynodonts (Therapsida, Cynodontia)

Schmitt

Martinelli

Kaiuca

et al. 2023

The Anatomical Record

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In this contribution we describe a new genus and species of gomphodontosuchine cynodont from the Late Triassic Hyperodapedon Assemblage Zone (AZ) of the Santa Maria Supersequence of southern Brazil, based on material collected 20 years ago. The new taxon, Santagnathus mariensis gen. et sp. nov., is based on numerous cranial and postcranial remains, which altogether provide data on several parts of the skeleton. Santagnathus mariensis is closely related to Siriusgnathus niemeyerorum and Exaeretodon spp. and expands the knowledge about gomphodontosuchine cynodonts. Morphologically, the new species has a skull bauplan particularly similar to S. niemeyerorum and E. riograndensis, differing from them by a unique combination of traits such as three upper incisors, the absence of a descending process in the jugal, a more posterior position of the postorbital bar and a preorbital region larger than the temporal one. The new traversodontid was found associated with the rhynchosaur Hyperodapedon sp., corroborating the assignment of the cynodont fossils to the Hyperodapedon AZ. We also provide comments on the status of the Argentine traversodontid cynodont Proexaeretodon vincei, typically considered a junior synonym of Exaeretodon argentinus, and here accepted as a valid taxon.

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New small reptile remains from the Late Cretaceous of Patagonia increase morphological diversity of sphenodontids (Lepidosauria)

Agnolín,

Aranciaga Rolando,

Chimento

et al. 2023

Proceedings of the Geologists' Association

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Unexpected new lizard from the Late Cretaceous of southern South America sheds light on Gondwanan squamate diversity

Cited by 5 publications

References 81 publications

Diuqin lechiguanae gen. et sp. nov., a new unenlagiine (Theropoda: Paraves) from the Bajo de la Carpa Formation (Neuquén Group, Upper Cretaceous) of Neuquén Province, Patagonia, Argentina

Diuqin lechiguanae gen. et sp. nov., a new unenlagiine (Theropoda: Paraves) from the Bajo de la Carpa Formation (Neuquén Group, Upper Cretaceous) of Neuquén Province, Patagonia, Argentina

Old fossil findings in the Upper Triassic rocks of southern Brazil improve diversity of traversodontid cynodonts (Therapsida, Cynodontia)

New small reptile remains from the Late Cretaceous of Patagonia increase morphological diversity of sphenodontids (Lepidosauria)

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