In the American Museum of Natural History, a partial skeleton is exhibited in the wall case to the left of the entrance of the Dinosaur Hall, and in an A-case near by are skulls of _Diplodocus_ and _Morosaurus_ and a model of the skull of _Brontosaurus_.

The Diplodocus skull is widely different from the other two in size and proportions and in the characters of teeth.
When the first remains of these amphibious Dinosaurs were found in the Oxford Clays of England, they were considered by Richard Owen to be related to the Crocodiles, and named Opisthocoelia.

Subsequently the finding of complete skeletons in this country led Cope and Marsh to place them with the true Dinosaurs and the latter named them Sauropoda.[13] Remains of these animals have also been found in India, in German East Africa, in Madagascar, and in South America, so that they were evidently widely distributed.

In the Northern world they survived until the Comanchic or Lower Cretaceous Period, but in the southern continents they may have lived on into the Upper Cretaceous or true Cretacic.

Some of the remains recently found in German East Africa indicate an animal exceeding either _Brontosaurus_ or _Diplodocus_ in bulk.
[Illustration: Fig.