Dinocerata

Dinocerata (Gr. deinos, 'terrible,' and keras, 'horn'), an extinct order of mammals, approaching the elephant in size and movements, remains of which have been found extensively in the Eocene lacustrine sediments of southern Wyoming. The dinocerata include three genera—Uintatherium (most primitive type), Dinoceras (intermediate form), and Tinoceras (youngest and most specialised). About thirty more or less distinct forms have been recognised. The feet were plantigrade, the fore-foot being larger than the hind-foot, and having five digits; the limbs were massive and heavy, but shorter than in the elephant; the skull was long and narrow, supporting on top three separate transverse pairs of high osseous protuberances or horn-cores, while the canine teeth were enormously developed in the male, and formed short, trenchant, decurved tusks; the nasal bones were elongated so as to form nearly half the length of the skull, though, as the neck was long enough to allow the head to reach the ground, there was probably no proboscis; finally, the brain was proportionately smaller than in any other known mammal, and even less than in some reptiles. See Professor O. C. Marsh's admirable monograph, published by the United States Geological Survey (1884).