Mapusaurus

Mapusaurus (Earth lizard) was a giant carcharodontosaurid carnosaurian dinosaur from the early Late Cretaceous (early Turonian stage), approximately 93.9 to 89.6 million years ago, of what is now Argentina. Mapusaurus was excavated between 1997 and 2001, by the Argentinian-Canadian Dinosaur Project, from an exposure of the Huincul Formation (Rio Limay Subgroup, Cenomanian) at Cañadón del Gato. It was described and named by paleontologists Rodolfo Coria and Phil Currie in 2006. The name Mapusaurus is derived from the Mapuche word Mapu, meaning 'of the Land' or 'of the Earth' and the Greek sauros, meaning 'lizard'. The type species, Mapusaurus roseae, is named for both the rose-colored rocks, in which the fossils were found and for Rose Letwin, who sponsored the expeditions which recovered these fossils. The designated holotype for the genus and type species, Mapusaurus roseae, is an isolated right nasal (MCF-PVPH-108.1, Museo Carmen Funes, Paleontología de Vertebrados, Plaza Huincul, Neuquén). Twelve paratypes have been designated, based on additional isolated skeletal elements. Taken together, the many individual elements recovered from the Mapusaurus bone bed represent most of the skeleton. Mapusaurus was a large theropod, but slightly smaller in size than its close relative Giganotosaurus, measuring up to long and weighing over at maximum. It has been determined that Mapusaurus was diagnosed on autapomorphies, or unique traits, in regions of the skeleton that Giganotosaurus does not preserve. Mapusaurus only differs from Giganotosaurus in lacking a second opening on the middle quadrate, and in some details of the topology of the nasal rugosities. The fossil remains of Mapusaurus were discovered in a bone bed containing at least seven to possibly up to nine individuals of various growth stages. Coria and Currie speculated that this may represent a long term, possibly coincidental accumulation of carcasses (some sort of predator trap) and may provide clues about Mapusaurus behavior.