Xenotarsosaurus is a genus of abelisaurid theropod dinosaur that lived during the Late Cretaceous of Argentina. In 1980 geologist Juan Carlos Sciutto discovered a rich fossil site six kilometres north of the Ocho Hermanos ranch in Chubut province. Among the fossils found there were some theropod remains. Later, a team led by Argentinian paleontologist José Fernando Bonaparte recovered some more theropod bones, possibly from the same individual. In 2016, its length was estimated to be 5.4 metres (18 ft).