Cranial anatomy of the Early Triassic trematosaurine Angusaurus (Temnospondyli: Stereospondyli): 3D endocranial insights and phylogenetic implications

• Published in: Journal of Iberian Geology
• Main Authors: Fernández-Coll, Meritxell, Arbez, Thomas, Bernardini, Federico, Fortuny, Josep
• Other Authors: University of Iceland Reykjavik, Centre de Recherche en Paléontologie - Paris (CR2P), Muséum national d'Histoire naturelle (MNHN)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS), Universitat Autònoma de Barcelona (UAB)
• Format: Article in Journal/Newspaper
• Language: English
• Published: HAL CCSD 2019
• Subjects: Stereospondyli; Trematosauridae; Trematosaurinae; Trematosauroidea; Trematosauria; [SDU.STU.PG]Sciences of the Universe [physics]/Earth Sciences/Paleontology; [SDV.BID]Life Sciences [q-bio]/Biodiversity; Antarc*; Antarctica; Antártida
• Online Access: https://hal.sorbonne-universite.fr/hal-02188788; https://hal.sorbonne-universite.fr/hal-02188788/document; https://hal.sorbonne-universite.fr/hal-02188788/file/FORTUNY_Josep.pdf; https://doi.org/10.1007/s41513-018-0064-4

International audience Background: Trematosaurines are a widespread group of early tetrapods (Temnospondyli, Stereospondyli) known from all continents except South America and Antarctica. They radiated rapidly during the Early Triassic just after the End Permian mass extinction and are of interest to understand the recovery of the ecosystems just after extinction. Trematosaurines disappeared during the Late Triassic.Objective: Herein, a re-description of the genus Angusaurus is presented based on a new specimen. This genus is known from the Early Olenekian (Early Triassic) of Russia and comprises four valid species, although the diagnostic characters that deine some of them are vague and controversial.Methods: The new specimen described, using MicroCT scanner and 3D digital modeling, sheds light on the anatomical details of the external and inner cranial structure, and provides new details of the neurocranium as well as the ontogeny of this genus.Results and Discussion: A cladistic analysis of trematosaurines (including most trematosauroids) confirms the problematic nature of some Angusaurus species and provides a basis for detailed discussion about the phylogeny of trematosaurines. Antecedentes: Los trematosaurinos son un grupo ampliamente distribuido de tetrápodos basales (Temnospondyli, Stereospondyli) conocidos de todos los continentes excepto Sud América y la Antártida. Este grupo se diversificó rápidamente durante el Triásico Inferior justo después de la extinción en masa del Pérmico terminal y son de interés para entender la recuperación de los ecosistemas justo después de la extinción. Los trematosaurinos desaparecieron durante el final del Triásico.Objetivo: En el presente trabajo se presenta una re-descripción del genero Angusaurus basada en un nuevo espécimen. Este género es conocido del Olenekiense Inferior (Triásico Inferior) de Rusia y comprende cuatro especies validas, aunque los caracteres diagnósticos que definen algunos de ellos son vagos y controvertidos.Métodos: El nuevo espécimen ...