This paper describes several fossil teeth coming from marine sediments from the Bajo Trapalcó locality, Río Negro province, Patagonia, Argentina. The ichthyofauna described here is composed by six different chondrichtyan taxa (Serratolamna serrata, Squalicorax pristodontus, Cretalamna appendiculata, Carcharias sp., Odontaspis sp. and cf. Pseudohypolophus mcnultyi) and two Teleostei of the genus Enchodus (aff. E. ferox and aff. E. gladiolus). Serratolamna serrata is the most abundant species, and it represents the southernmost record for the species and the first record for Argentina. The records of Enchodus, Squalicorax pristodontus and cf. Pseudohypolophus mcnultyi, constitute the first mention for these taxa in Argentina. The taxa described here characterize the paleoichthyofaunas of the Upper Cretaceous seas from different regions of the world, contributing with new information toward the comprehension of the Mesozoic ichthyofunas from the southern regions of South America.
Maastrichtian; Serratolamna serrata; Lamniformes; Squalicorax; Enchodus
