ANCYLOPODA or CHALICOTHEROIDEA, a group of extinct large-bodied herbivorous mammals distinguished by the combination of large claws on the feet with herbivorous molar teeth of the type technically known as buno-lopho-selenodont (cone-ridge-crescent tooth). The first known remains of these animals consisted of a large claw-like bone found in the Upper Miocene formation near Eppelsheim, Germany. This was pro nounced by Cuvier in 1825 to represent "un pangolin gigan tesque." Similarly, in North America the claw-like bones now known to pertain to Moropus (see below) were at first believed to have belonged to edentates, but the entire group is now known to consist of strangely modified hoofed mammals belonging to the order Perissodactyla (q.v.).
Through recent discoveries the best known member of the group is Moropus elates, nearly complete skeletons of which, from the Lower Miocene of western Nebraska, are exhibited in the natural history museums of New York and Pittsburgh. This animal stood about 6ft. high at the shoulders. In general appear ance it somewhat resembled a large horse, especially in the head and neck ; but the feet were short, each ending below in three clawed digits, the claw on the inner side of the forefoot (corre sponding to the nail of the second finger of the human hand) being greatly enlarged. Very possibly these claws (which repre sent highly modified hoofs rather than true claws) were used in scraping the ground in search of food or water. The front teeth or incisors were small and the canine teeth reduced. In the upper molar teeth the crown pattern exhibited a combination of crests and hillocks across which the U-shaped lower molars moved. The skull and dentition exhibit a curious combination of characters found elsewhere separately among the horses and earlier titanotheres, to both of which families the chalicotheres are remotely related. The earliest known member of the group (Eomoropus) occurs in the middle Eocene of Wyoming. It was about as large as a sheep. Its skull and teeth, while clearly fore shadowing those of Moropus, also indicate its derivation from still older and more primitive perissodactyls. Among the later members of the group Macrotlieriurn magnum was a beast of elephantine bulk. The known range of the group was from the middle Eocene of Wyoming to the Pliocene of China.
See H. F. Osborn, "Eomoropus, an American Eocene Chalicothere," Bull. Amer. Mus. Nat. Hist., vol. xxxii., p. 261 (1913) ; W. J. Holland and O. A. Peterson, "The Osteology of the Chalicotheroidea," Memoirs of the Carnegie Museum, vol. iii., No. 2 (1914) .
(W. K. G.)