Chigutisaurid amphibians from the Upper Triassic of Argentina and their phylogenetic relationships

A revision of the temnospondyl chigutisaurids from the Upper Triassic of Ar gentina is presented. The validity of the taxa originally proposed is discu ssed in the light of new material. The genus Pelorocephalus (Chigutisaurida e) is diagnosed by the presence of a longitudinally keeled cultriform proce ss, occurrence of the anterior Meckelian fenestra on the suture between spl enial and postsplenial, location of the chordatympanic foramen on the conta ct between angular and prearticular, and exposure of the angular on the lin gual mandibular surface. Three species, Pelorocephalus mendozensis, P. tena x and P. cacheutensis, are distinguished mainly by differences in the struc ture of the occiput. Phylogenetic relationships among all known representat ives of this family, including taxa from India and Australia, are discussed .