MACNBR   00242
MUSEO ARGENTINO DE CIENCIAS NATURALES "BERNARDINO RIVADAVIA"
Unidad Ejecutora - UE
congresos y reuniones científicas
Título:
THE PHYLOGENETIC RELATIONSHIPS OF PERMO-TRIASSIC ARCHOSAUROMORPHS (SAUROPSIDA: DIAPSIDA)
Autor/es:
EZCURRA, M. D.
Lugar:
Capital Federal
Reunión:
Congreso; XXX Jornadas Argentinas de Paleontología de Vertebrados; 2016
Institución organizadora:
Museo Argentino de Ciencias Naturales
Resumen:
The early evolution of archosauromorphs during the Permo-Triassic constitutes an excellent case study to shed light on evolutionary radiations in deep time and the timing and processes of biotic recovery after a mass extinction. However, macroevolutionary studies of early archosauromorphs are currently limited by poor knowledge of their phylogenetic relationships. A new data matrix composed of 96 species or specimens and 600 osteological characters was assembled and analysed to reconstruct the higher-level relationships of basal archosauromorphs and specially the interrelationships among proterosuchian archosauriforms. The results of the cladistic analysis include a polyphyletic ?Prolacertiformes?, ?Protorosauria? and ?Proterosuchia?. Choristoderans are either found as basal lepidosauromorphs or archosauromorphs. Prolacertids, rhynchosaurs, allokotosaurians and tanystropheids are the major successive sister clades, respectively, of Archosauriformes. The Early Triassic Tasmaniosaurus is recovered as the sister-taxon of Archosauriformes. Proterosuchidae is unambiguously restricted to five species that occur immediately after and before the Permo-Triassic boundary. Erythrosuchidae is composed of eight Early and Middle Triassic species. Doswelliids and proterochampsids are closely related to each other than to other archosauromorphs. Euparkeria is one of the sister-taxa of the clade composed of proterochampsians and archosaurs. Phytosaurs are recovered as the sister-taxa of all other pseudosuchian archosaurs, thus contrasting with recent proposals that this clade is the sister-taxon of Archosauria. Based on these results, the evolutionary history of archosauriforms during the Early Triassic can be subdivided in a first phase characterized by the short-lived ?disaster-clade? Proterosuchidae and a second phase that witnessed the initial morphological and probably palaeoecological diversification of the group.