Period: Early Cretaceous
Order, Suborder, Family: Ornithischia, Thyreophora, Stegosauridae
Location: Asia (People's Republic of China)
Length: 20 feet (6 meters)
As far as paleontologists know, stegosaurs almost became extinct at the close of the Jurassic Period. Very few lived during the Cretaceous Period. Craterosaurus, known only from a piece of a vertebra, is from the Early Cretaceous of Great Britain. Another stegosaurian, Dravidosaurus, is known from remains from the Late Cretaceous of India. The undescribed stegosaurian "Monkonosaurus" from Tibet may also be of Early Cretaceous age. But the best-documented Early Cretaceous stegosaur is Wuerhosaurus.
Presently the latest known Chinese stegosaurian, Wuerhosaurus homheni is based on a fragmentary skeleton lacking the skull and on three tail vertebrae of a second animal, all found in the Tugulo Formations near the northwestern part of the Junggar Basin. It was described by Dong Zhiming in 1973. Two armor plates found with the skeleton are thin, long, low, and somewhat semicircular. They are quite different from the tall, triangular plates of other stegosaurians.
Its body was broad, as shown by its wide pelvic bones, and its front limbs were quite short. Although the back limbs have not been found, the shortness of the front limbs shows that the animal had an arch in its back-perhaps even more curved than in Stegosaurus. Comparing bones with those of other stegosaurs shows that Wuerhosaurus was most closely related to Stegosaurus, which is the only stegosaur that had an alternating arrangement of armor plates. Some Chinese paleontologists think Wuerhosaurus may have had alternating plates, but since only two plates were found with the skeleton, there is not enough material to be certain.