Palaeotherioi (Cuv.; Gr. 7rahn6c, ancient, and, animal), the type of a tribe of fossil ungulates belonging to the family of perissodactyla (Owen), or those having an uneven number of toes, intermediate between the tapir and the rhinoceros. The form was like that of the tapir; the raised nasals show that it had a small flexible proboscis; the feet were three-toed; it had projecting canines, and molars I, the upper like those of the rhinoceros, the first smallest and single lobed, and the lower formed by two successive crescents with their convexity external, the first single and the last one trilobed. Several species are described by Cuvier and others, of which the largest and best known is the P. magnum (Cuv.), of the size of a horse, but of a stouter form; others vary in size from that of a hog and sheep to that of a hare. They belong especially to the gypsum of Europe (eocene), are abundant in the plaster quarries of Montmartre, near Paris, and extend even into the lower miocene; the species differ little, except in size.

Palaeotherium (restored).

Palaeotherium (restored).