Complete at 55%. It is one of the best examples of Allosaurus ever found.
Dimensions of the skeleton:
Height: 1.70 m
Length: 4.58 m
Width: 54 cm
Dimensions with the base:
Overall height: 2.00 m
Length: 4.58 m
Width: 80 cm
Age: Upper Jurassic (154-148 million years). Discovered at Ten Sleep, Washakie County, Wyoming (United States of America).
Geological formation: Morrison.
Dug out of the ground where it has been imprisoned for millennia, this fossilized skeleton has been restored by American paleontologists. It is a middle-aged Allosaurus, with an estimated upper age limit of between 22-28 years of age. It belongs to the suborder of Theropods, bipedal and carnivorous dinosaurs that dominated the landmasses of the Earth for more than 150 million years. The name Allosaurus derives from the Greek hallos, meaning « different », and sauros, meaning « lizard », because of the appearance of its vertebrae which seemed different from those of other reptiles. It lived in Laurasia, in present-day North America and Europe.
Allosaurus is one of the largest Theropods, suborder that includes Tyrannosaurus and others Carnotaurus, as well as smaller dinosaurs like Deinonychus or the tiny Microraptor, less than one-meter long. It is estimated that it could reach exceptionally up to 10 to 12 meters long and weigh from 1 to 2 tons. Allosaurus is a larger version of its contemporary close relative: the Megalosaurus. Its skull can measure up to 85-90 centimeters. While massive, it is not heavy thanks to the presence of several large openings, « windows », located between different bones of the skull, allowing to lighten and reduce the solid structure in a network of bone stems. The two bony bumps above its eyes and the thin crest of the intraocular area, all the way to the tip of the muzzle, give its head a special shape that distinguishes it from Megalosaurus.
Its teeth, easily falling out, were continually shed and replaced. They are serrated and curved. Studies show that because of the quite weak pressure exerted by its jaw, Allosaurus must give great headbutts downward to slice the flesh of his prey, using its teeth like axes. The forelegs are shorter than the hindlimbs and have three fingers, ending in long, strongly curved claws up to 15 cm long. These members are agile and powerful. The three sharp claws on each leg allow him to manipulate his prey and grip it.His hind legs, larger and more muscular, allow him to run up to 30 or even 50 km/h. The claws of the toes are less developed than those of the legs before the more like clogs.
Leaving lands close to watercourses, forests, and undergrowth to dinosaurs of smaller size, the heavier and more massive Allosaurus prefers the vast plains of savannah.
Allosaurus is one of the most ferocious predators of the Jurassic. Carnivorous and even scavenger, it is certainly the nightmare of all Ornithopods, Stegosaurids, and Sauropods, such as Diplodocus, Brachiosaurus, and Camptosaurus, living near him. Moreover, one of his first names, Antrodemus, or « the nightmarish dragon », reflects its hegemony very well. Some theories suggest that Allosauruslives in groups, cares for the young, hunt in packs and protects the clan. Other theories hold that Allosaurus cannibalizes and can kill its congener or take advantage of its weakness to eat it. Allosaurus was assigned to Allosauridae family and it includes four species of lower rank: A. Fragilis (described for the first time by Othniel Charles Marsh in 1877), A. Jimmadsenni, A. Europaeusand A. Lucasi (described in 2014 by the discovery of two specimens, one adult and the other juvenile).