The African cynodont Aleodon (Cynodontia, Probainognathia) in the Triassic of southern Brazil and its biostratigraphic significance

摘要: In this contribution we report the first occurrence of enigmatic African probainognathian genus Aleodon in Middle-early Late Triassic several localities from state Rio Grande do Sul southern Brazil. is unusual among early probainognathians having transversely-expanded postcanine teeth, similar to those gomphodont cynognathians. This was previously known Manda Beds Tanzania and upper Omingonde Formation Namibia. The Brazilian record based upon multiple specimens representing different ontogenetic stages, including three that were referred sectorial-toothed Chiniquodon theotonicus. We propose a new species (A. cromptoni sp. nov.) on Additionally, tentatively refer one specimen Namibia taxon, strengthening biostratigraphic correlations between these strata. Inclusion A. phylogenetic analysis eucynodonts recovers it as sister-taxon brachyrhamphus within family Chiniquodontidae. discovery numerous supposedly monospecific samples Brazil raises concerns about chiniquodontid alpha taxonomy, particularly given extremely broad geographic distribution Chiniquodon. records traversodontid Luangwa supports hypothesis at least two subzones can be recognized Dinodontosaurus Assemblage Zone.