(Strange tarsus lizard).
Named By: Ricardo Martínez, Olga Giménez, Jorge Rodríguez & Graciela Bochatey - 1986.
Classification: Chordata, Reptilia, Dinosauria, Saurischia, theropoda, Abelisauridae?
Species: X. bonapartei (type).
Size: Roughly estimated to be about 5.4 meters long.
Known locations: Argentina, Chubut Province - Bajo Barreal Formation.
Time period: Cenomanian to Turonian of the Cretaceous.
Fossil representation: Two anterior dorsal (back) vertebrae and a right hind limb.
upon fossil remains first discovered in 1980, Xenotarsosaurus
named because of the complete fusion between the astragalus and
calcaneum bones of the ankle, something that is quite unusual for a
theropod dinosaur. At the time of the original description, the
rear leg of Xenotarsosaurus was shown to share some
the better known Carnotaurus,
logically leading to the identification
of Xenotarsosaurus as an abelisaurid.
1989 study Coria
et al. led to an alternative notion that Xenotarsosaurus
may in fact
be an indeterminate neoceratosaurian theropod. Additionally at the
time of its original description, Xenotarsosaurus
was thought to come
from the Campanian of the Cretaceous, but a later re-assessment of
the Bajo Barreal Formation now means that Xenotarsosaurus
lived during the Cenomanian/Turonian stages of the Cretaceous.
Xenotarsosaurus was likely one of the principal predators of the Bajo Barreal Formation, with possible prey species including the hadrosaurid Secerosaurus, and titanosaurian sauropods like Drusilasaura.
- Xenotarsosaurus bonapartei nov. gen. et sp. (Carnosauria, Abelisauridae), un nuevo Theropoda de la Formacion Bajo Barreal, Chubut, Argentina - Ricardo Martínez, Olga Giménez, Jorge Rodríguez & Graciela Bochatey - 1986.
- Sobre Xenotarsosaurus bonapartei Martínez, Giménez, Rodríguez y Bochatey, 1986; un problematico Neoceratosauria (Novas, 1989) del Cretácico de Chubu - R.A. Coria & J. Rodríguez - 1993.
- Allometry and body length of abelisauroid theropods: Pycnonemosaurus nevesi is the new king. - Cretaceous Research. 69: 71–89. - O. N. Grillo & R. Delcourt - 2016