The scientific name of the terror beast is Deinoterium, which means "terrifying beast". The terror beast belongs to the mammalian phylum, long nosed order, and terror beast family. The terror beast is a huge proboscid animal, with some individuals reaching a height of up to 5 meters, making it the third largest known terrestrial mammal to have existed. The lower jaw of the terror beast has a pair of long fangs that curve downwards and backwards, without the upper fangs found in other long nosed animals. The terror beasts appeared in the Miocene and lived until the early Pleistocene. Fossils of terror beasts have been found in all major excavation sites in East Africa, including Hadar, Letoli, Olduvai Gorge, and Lake Turkana.