[4] Based on elements of the postcranial skeleton, Shoshonius is inferred to be a generalized, arboreal quadruped with some affinities for vertical climbing and leaping.

[6] Current research places Shoshonius as the sister group of Tarsius within the suborder Haplorhini, a monophyletic clade which includes tarsiers, monkeys, apes, and humans.

[8] Shoshonius has larger eye orbits in proportion to its skull length when compared to other Eocene omomyids and the snout is much smaller, both of these traits are also observed in tarsiers.

[4] Additionally, Shoshonius retains some dental morphologies that are found in early primitive primates, namely, small lower incisors, indicating their dentition was not specialized for gouging tree bark as seen in other omomoyids.

[5] Additionally, morphology of the upper limb of Shoshonius does not support vertical clinging and leaping as a locomotor behavior and instead shows similarities with other omomyids that were most likely more generalized quadrupeds.