Chondrichthyans from the base of the Irati Formation (Early Permian, Parána Basin), São Paulo, Brazil

Three species of chondrichthyans are reported from conglomeratic sandstone at the base of the Lower Permian (Artinskian) Irati Formation (Paraná Basin) near Rio Claro, São Paulo State, Brazil. The fossils include: 1) dispersed teeth of the petalodont Itapyrodus punctatus Silva Santos 1990, first described from the Permian (Artinskian) Pedra do Fogo Formation, Parnaiba Basin, Northeast Brazil; 2) a new species of tooth of the Order Orodontiformes; and 3) a new species of finspine of the Order Ctenacanthiformes. These fossils occur in an allochthonous assemblage of vertebrate remains including other Chondrichthyes, Xenacanthiformes and cladodonts, paleonisciform bony fish, and tetrapods. This discovery is a significant contribution to the sparse record of South American Chondrichthyes from the Early Permian and raises questions regarding the paleoenvironmental adaptations among these fish within Paleozoic basins of Brazil at this time.