The Complete Femur of an Allosaurus

Faster and less bulky than a T. rex, but larger and more powerful than a Velociraptor, Allosaurus was easily amongst the most physically intimidating dinosaurs. With a total body length of 30 feet (9 meters), weights approaching 3,500 pounds (1,600 kg), and three large hand claws (as opposed to T. rex's two), you'd be hard-pressed to find a more perfectly proportioned killing machine.

Stalking stegosaurs, ornithopods, and even small sauropods, Allosaurus used muscular legs, serrated teeth, and machete-like jaws to secure its spot atop the late Jurassic North American food chain. Scientific debate continues to rage with respect to the hunting strategies these carnivores employed—some paleontologists believe Allosaurus was an intelligent, social creature that hunted in packs, while others theorize a more solitary existence. Either way, without the use of swift and muscular legs anchored by femora like the sculptural specimen offered here, their search for food would have proven vastly more difficult.