Abstract

Late Jurassic South American theropod faunas are still extremely poorly known, with large-sized ceratosaurids
and megalosaurids having been identified on the basis of isolated teeth, whereas the only named taxa, Chilesaurus
and Pandoravenator, are probable tetanurans of uncertain affinities. Here we describe two new specimens of
medium-sized to large theropods from the Oxfordian-Kimmeridgian Ca˜nad on Calc areo Formation of Chubut,
Argentina; an isolated and rather well-preserved anterior cervical vertebra and a very fragmented, but associated
assortment of bones, including cranial and vertebral remains. Both specimens show ceratosaurian and, most
probably, abelisaurid affinities. A faunal analysis underlines the relative abundance of ceratosaurs and the
absence of coelurosaurs as main differences of Late Jurassic Gondwanan theropod faunas from their Laurasian
counterparts. The presence of abelisaurids in both the Tendaguru Formation and the Ca˜nad on Calc areo Formation
indicates a wide distribution of this clade already in the Late Jurassic in the Southern Hemisphere.