Piveteausaurus

Extinct genus of dinosaurs

Piveteausaurus (meaning "Jean Piveteau's lizard") is a genus of theropod dinosaur known from a partial skull discovered in the Middle Jurassic Marnes de Dives formation of Calvados, in northern France and lived about 164.7 161.2 million years ago. In 2012 Thomas Holtz gave a possible length of 11 meters (36 feet).

The partial braincase that became the type specimen of Piveteausaurus was first described in 1923 by French paleontologist Jean Piveteau in illustrations and photographs of the specimen (MNHN 1920 7). The braincase is comparable in size to that of a large Allosaurus, and resembles that of another megalosauroid, Piatnitzkysaurus from Argentina. Piveteau grouped this partial skull with other specimens found earlier in that locality and described in 1808 by French naturalist Georges Cuvier. In 1861 English paleontologist Richard Owen assigned the fragments to the species Streptospondylus cuvieri, and Piveteau included the skull he found in the same species. Later these rocks were reevaluated as older (Upper Callovian, Middle Jurassic, ~164 million years old). MNHN 1920 7 was reevaluated in 1964 by Alick Walker as part of his work on Ornithosuchus and the evolution of the Carnosauria. Later the braincase would be regarded by Gregory S. Paul as a species of Proceratosaurus (P. divesensis), but this assignment was rejected by other researchers. While the braincase appears to be distinct, the limited remains mean Piveteausaurus has not been easy to classify. It has been compared to Ceratosaurus, Eustreptospondylus,

The phylogenetic position of Piveteausaurus according to Carrano et al. (2012) is shown by this cladogram: