Descrição de uma nova espécie de anfíbio (Tetrapoda Temnospondyli) para a formação Rio do Rasto (Permiano da Bacia do Paraná) e revisão do status filogenético de Archegosauroidea

Abstract

Temnospondyli is a very diverse group of basal tetrapods that appeared in the Early Carboniferous, going through major phases of radiation and extinction, with peaks of diversity during Permian and Triassic. It includes the Archegosauroidea, an abundant group in Eastern Europe with a few records from South America (so far restricted to Brazil). Achegosauroidea is divided into two families, Archegosauridae e Melosauridae. Until this contribution, unquestionable records of formally described archegosauroids from Gondwana belong to the Archegosauridae, as follows: The platyoposaurinae Prionosuchus plummeri from the Maranhão state (Pedra de Fogo Formation) and Bageherpeton longignathus from the Rio Grande do Sul state (Rio do Rasto Formation). This work presents the description and phylogenetic analysis of the first indubitable tryphosuchine outside Eastern Europe. The new material (UNIPAMPA PV 00137) consists in a partially complete skull collected in 2008 in the Posto Queimado locality (that also belongs to the Rio do Rasto Formation) from São Gabriel municipality, Rio Grande do Sul state. In the phylogenetic analysis presente Russia) in the Permian of Gondwana provide new insights about its radiation and dispersion, which may have happend on Laurasia with Konzhukovia being part of the first irradiation of archegosauroid to Gondwana or with konzhukovia originated on Gondwana and migrated to Laurasia, where the derivated species evolved. Besides, the fact that Konzhukovia belongs to a basal family to Stereospondyli reinforces the hypothesis that these ones are originated and diversificated in the West of Gondwana before the end of Permian. However, it is unlikely the hypothesis that the Stereospondyli may have stayed in a refuge in the East of Gondwana and may have diversificated after the great extinction in the end of Paleozoic period.