The Early Evolution of Rhynchosaurs

 

Autores
Ezcurra, Martin Daniel; Montefeltro, Felipe C.; Butler, Richard J.
Tipo de recurso
artículo
Estado
Versión publicada
Año de publicación
2016
País
Argentina
Institución
Consejo Nacional de Investigaciones Científicas y Técnicas
Repositorio
CONICET Digital (CONICET)
Descripción
The rhynchosaurian archosauromorphs are an important and diverse group of fossil tetrapods that first appeared during the Early Triassic and probably became extinct during the early Late Triassic (early Norian). Here, the early evolution of rhynchosaurs during the Early and early Middle Triassic (Induan-Anisian: 252.2-242 Mya) is reviewed based on new anatomical observations and their implications for the taxonomy, phylogenetic relationships and macroevolutionary history of the group. A quantitative phylogenetic analysis recovered a paraphyletic genus Rhynchosaurus, with “Rhynchosaurus” brodiei more closely related to hyperodapedontines than to Rhynchosaurus articeps. Therefore, a new genus is erected, resulting in the new combination Langeronyx brodiei. A body size analysis found two independent increases in size in the evolutionary history of rhynchosaurs, one among stenaulorhynchines and the other in the hyperodapedontine lineage. Maximum likelihood fitting of phenotypic evolution models to body size data found ambiguous results, with body size evolution potentially interpreted as fitting either a non-directional Brownian motion model or a stasis model. A Dispersal-ExtinctionCladogenesis analysis reconstructed the areas that are now South Africa and Europe as the ancestral areas of Rhynchosauria and Rhynchosauridae, respectively. The reconstruction of dispersal events between geographic areas that are broadly separated paleolatitudinally implies that barriers to the dispersal of rhynchosaurs from either side of the paleo-Equator during the Middle Triassic were either absent or permeable.
Idioma
inglés
OAI Identifier
oai:ri.conicet.gov.ar:11336/44040
Enlace del recurso
http://hdl.handle.net/11336/44040
Nivel de acceso
Acceso abierto
Materia
Permo-Triassic
Diapsida
Archosauromorpha
Body size
Phylogeny
Paleobiogeography
Meteorología y Ciencias Atmosféricas
Ciencias de la Tierra y relacionadas con el Medio Ambiente
CIENCIAS NATURALES Y EXACTAS