Shoshonius lived about 50 million years ago during the late early Eocene era, with specimens found in Central Wyoming. Shoshonius belongs to the extinct primate family Omomyidae, and shares many features with modern-day tarsiers. Shoshonius had large eye sockets and numerous details in the ear region which are absent in other primates except tarsiers, making it too specialized to be ancestral to both tarsiers and higher primates (including humans).