Metacheiromys tatusia (aka M. marshi Wortman 1903, Osborn 1904, Simpson 1931, AMNH 11718, 25cm presacral lengh; YPM 12903 holotype is chimaera, part primate; Middle Eocene; ) was originally considered a primate, then an edentate and then as a palaenodont. Here it nests with Vulpavus ovatus and Alocodontullum in the Carnivora close to Protictis. Few to no teeth line the jaws, except for the upper and lower canines, which were retained. The sacrum appears odd in that only the posterior sacral ribs attached to the ilia. Manual digts 1 and 5 are absent. Pedal digit 5 is absent.
Alocodontullum atopum (Rose, Bown and Simons 1978; Rose, Emery and Gingerich 1992; early Eocene, 45 cm in length; UM 93740) is a close relative of Metacheiromys differing chiefly in relative metatarsal and toe lengths and having flat-cusped teeth poterior to the fang-like canines. Claws and forelimbs appear ready to dig. Hands and feet are relatively larger. Mandible is relatively smaller.
Rose, Emery and Gingerich 1992 nest Alocondontulum in a clade named Epoicotheriidae, but Epoicotherium and Xenocranium nest elsewhere, far from vulpavids. |