Abelisaurus

Reconstruction of the skull of Abelisaurus in the exhibition Dinosaurs of Patagonia.

• Argentina ( Anacleto Formation)

• Abelisaurus comahuensis

Abelisaurus is a genus theropod dinosaur from the group of Ceratosauria. This large, bipedal running predator is known only by an incomplete skull (early to middle Campanian ) comes from the Upper Cretaceous of Argentina. Abelisaurus is the eponymous representative of Abelisauridae and Abelisauroidea. The genus was described in 1985 by José Fernando Bonaparte and Fernando Novas with the previously single type Abelisaurus comahuensis first time scientifically.

The name Abelisaurus ( " Abel's lizard" ) honors Roberto Abel, director of the Museo de Cipolleti and discoverer of the fossil. The second part of the species name, comahuensis, has the region Comahue, from which comes the fossil.

Features

Abelisaurus is estimated at a length 6.5 to 10 m, a waist height of 2 m and a weight of about 1.4 to 4 tonnes.

The skull found is reconstructed to a maximum length of 85 cm. He was tall and narrow, the skull windows were large. The skull was flattened, in particular, had the paired nasal bone on the surface conspicuous irregularities including small tapering projections.

System

Bonaparte and Novas (1985) Abelisaurus first as a representative of the Carnosauria; in this group almost all Großtheropoden were previously combined. In order to take into account the marked differences that distinguishes Abelisaurus compared with other then-known theropods, these researchers presented a new family within the Carnosauria on which Abelisauridae, which initially contained a single representative Abelisaurus. Today, a basal ( original ) group of theropods which Abelisauridae not be classified within the Carnosauria, but within the Ceratosauria.

Within the Ceratosauria the Abelisauridae are summarized together with the Noasauridae to the group Abelisauroidea. Within the Abelisauridae Abelisaurus is often viewed as basal representatives, since the flattened skull roof for more original species is typical ( plesiomorphes feature ). Carrano and Sampson (2008) noted, however, that other Abelisauriden as Indosuchus have a flattened skull roof, and that the relationships of Abelisaurus must be re- examined within the Abelisauridae.

Discovery

The skull ( holotype, specimen number 11908 ) was discovered in 1983 by Roberto Abel at Lago Pellegrini in the Argentine province of Rio Negro. He comes from the Anacleto Formation, a layer member of the Neuquén Group. The skull is preserved for the most part; there is a lack of the right upper jaw ( maxilla ), the zygomatic bone ( Jugale ), the Quadratojugale, the squamosal ( Squamosale ) and the majority of the palate.