Size and Weight:
Carnotaurus is one of those dinosaurs that looks like it didn't come out of the oven quite right: its arms were small and stubby enough to make those of Tyrannosaurus Rex seem gigantic by comparison, and the thick, stubby horns over its eyes were too small to be of much use, except perhaps as a sexually selected characteristic. Less embarrassingly, a new study has shown that the tail of Carnotaurus was unusually straight and muscular, implying that this dinosaur was able to reach very respectable running speeds in pursuit of prey, and Carnotaurus also seems to have possessed an unusually thick neck, which may (or may not) have had something to do with its stunted and puny arms.
Carnotaurus is known by a single fossil specimen, missing only bits of the tail and hind legs, discovered in Argentina in 1985 by the famous paleontologist Jose Bonaparte. Close examination of this skeleton enabled Bonaparte to classify Carnotaurus as an "abelisaur," and thus closely related to the mysterious South American theropod Abelisaurus. The one-ton Carnotaurus may well have been the biggest abelisaur yet identified, its only possible competition being the similarly sized (and awkwardly named) Ekrixinatosaurus, or "explosion-born lizard."
The combination of Carnotaurus' tiny arms, large bulk, and presumed running speed has made this dinosaur unusually popular in Hollywood, especially considering that it's barely 25 years old (compared to Tyrannosaurus Rex and Triceratops, which have been well known for over a century). Most recently, Carnotaurus was the featured heavy in Steven Spielberg's short-lived TV series Terra Nova, and it also had leading roles in Disney's 2000 movie Dinosaur and Michael Crichton's 1995 Jurassic Park sequel, The Lost World.