Smilodectes gracilis (Wortman 1903; Middle Eocene, North America, 55mya, 27cm snout-vent length) is traditionally considered an adapid (lemur-sister) primate. Here it is transitional to higher New World monkeys, tarsiers, Old World monkeys and apes, in that order. It is derived from a sister to Notharctus.
Distinct from Notharctus, the rostrum is shorter. Four premolars and three molars are present in the maxilla and dentary. The dorsal skull bones are unfused. A smaller muzzle and larger orbits indicates a shift from olfactory to visual acuity. The ulnocarpal joint of Smilodectes is similar to that of extant haplorhines and other eutherians, |
