The species of Deinotherium are compared here. The size of the genus is generally similar to the size of the modern African Elephant, but a little bit taller. The tusk situation is obviously radically different for the two enormous mammals, but the general plan of the tusks is the same in both. Tusks are extremely large dental growths in both taxa. The tusks of Deinotherium, as can be seen here, extend ventrally, and eventually caudally, from the mandible. The recurved and tapering tusks are a key identifying feature of the animal. They may have been used to dig roots or as defensive tools. They could also have been used to pull down branches. There may never be a definitive answer to that question, but they are quite interesting and unique features to look at.