Xuanhanosaurus (Greek for "Xuanhan lizard"); pronounced zwhan-han-oh-SORE-us
Forests of Asia
Late Jurassic (155 million years ago)
Size and Weight:
About 20 feet long and 500 pounds
Powerful arms and legs; large, fish-shaped head
Like many dinosaurs, Xuanhanosaurus is known only from scattered bones, mostly from its back, shoulders and arms. Still, enough has been discerned about similar theropods of the Jurassic period to reconstruct a convincing picture: Xuanhanosaurus had unusually long, powerful arms and legs, and its distinctive, roundish head looked almost comical (although the small, quivering herbivores it fed on probably were not amused). The discoverer of Xuanhanosaurus, the Chinese paleontologist Dong Zhiming, has caused a stir by suggesting that this dinosaur walked (at least occasionally) on all fours--which would make it the only theropod ever to have done so. However, most other paleontologists believe Xuanhanosaurus possessed the bipedal gait typical of other predatory dinosaurs.