Mesoamericus bilobatus, also known commonly as O'Shaughnessy's galliwasp, is a species of lizard in the family Diploglossidae.

A 2021 study found M. bilobatus to not belong to the genus Diploglossus (which is otherwise only found in South America and the Caribbean), but rather to belong to the monotypic genus Mesoamericus in the subfamily Siderolamprinae.

[2][3] M. bilobatus is found in Costa Rica, Nicaragua, and Panama.

[2] The preferred natural habitat of M. bilobatus is forest, at altitudes of 2–1,360 m (6.6–4,461.9 ft).

[1] M. bilobatus has sheathed claws,[2] which Boulenger (1885) described as "claws nearly entirely concealed in a large compressed sheath formed of a larger supero-lateral and a smaller inferior scale".