Chilantaisaurus Claw cast. Theropod Dinosaur from the Late Cretaceous (Approximately 92 MYA). Chilantaisaurus fossils are found in the Cretaceous Ulansuhai Formation of China. The largest ones were about 13 m (43 ft). They are a Carnosaur believed to be related to Allosaurus; but, they also have unusual arms and claws- very similar to Spinosaurids. Claw size: 5 cm.