TINOCERAS, an extinct genus of herbivorous mammals from the eocene formation of Wyoming and Utah, the first known members of the new order dinoeeraa, so named from the best known genus dinoceras, which may be regarded as the typical one, and characterized as follows: Skull long and narrow; facial portion much extended. The upper surface of the skull has three pairs of bony processes, which are regarded as hav ing been the support of horns (whence the name " terrible-horned"). The smallest pair are near the end of the nasal bones; a larger pair spring from the cheek bones in front of the orbits; the largest pair are on the cranial parietal bones, and are situated upon a. large crest or ridge which extend from near the orbits around the lateral and posterior margins of the cranium. Dental formula, vm m As in rumi 3-3' 1-1' 3-3' 3-3' nants the premaxillaries are without teeth, and probably also supported a callous pad.
The upper canine teeth, strongly set in the maxillary bones, are decurved, trenchant, and separated by a diastema from the molar teeth. The cervical vertebra: are longer than in the elephant, while the legs are short, and the skull elongated, allowing the mouth to easily reach the ground. A proboscis was therefore not needed, and probably did not exist. Feet short and stout; five toes before and behind. The brain cavity ia the remarkable feature, and indicates a brain smaller in proportion than that of any oth tr mammal, smaller even than that of some reptiles, the cerebral hemispheres being extremely small, not overlapping either the cerebellum or the olfactory lobes. Some of these animals were nearly as large as the elephant.