The stapes of thrinaxodon seeley, 1894 and galesaurus owen, 1859: A case of study for intraspecific variability in basal cynodonts

We surveyed the stapedial anatomy of Thrinaxodon liorhinus Seeley, 1894 and Galesaurus planiceps Owen, 1859, two iconic Early Triassic basal cynodonts. The complete characterization of this bone and the analysis of its morphological variability along the ontogeny within each taxon were possible thro...

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Detalles Bibliográficos
Autores: Gaetano, Leandro Carlos, Abdala, Nestor Fernando
Tipo de recurso: artículo
Estado:Versión publicada
Fecha de publicación:2021
País:Argentina
Institución:Consejo Nacional de Investigaciones Científicas y Técnicas
Repositorio:CONICET Digital (CONICET)
Idioma:inglés
OAI Identifier:oai:ri.conicet.gov.ar:11336/173713
Acceso en línea:http://hdl.handle.net/11336/173713
Access Level:acceso abierto
Palabra clave:EARLY TRIASSIC
EPICYNODONTIA
GALESAURUS
STAPES
THRINAXODON
https://purl.org/becyt/ford/1.5
https://purl.org/becyt/ford/1
Descripción
Sumario:We surveyed the stapedial anatomy of Thrinaxodon liorhinus Seeley, 1894 and Galesaurus planiceps Owen, 1859, two iconic Early Triassic basal cynodonts. The complete characterization of this bone and the analysis of its morphological variability along the ontogeny within each taxon were possible through the study of eleven elements of Thrinaxodon Seeley, 1894 and nine of Galesaurus Owen, 1859. Our results highlight notable qualitative and quantitative differences among specimens of the same species. Stapes growth model in Galesaurus shows a positive allometry on the lateromedial length and on the anteroposterior width, whereas in Thrinaxodon there is a negative allometry in the anteroposterior width but the lateromedial length is isometric. This study offers a counterintuitive result of inordinate high intraspecific morphological variation of the stapes of basal non-mammaliaform cynodonts.