Theretairus is a Late Jurassic genus of sphenodont reptile from the Morrison Formation of western North America, present in stratigraphic zones 5 and 6.
Species taxanomy provided by GBIF Secretariat (2022). GBIF Backbone Taxonomy. Checklist dataset https://doi.org/10.15468/39omei accessed via GBIF.org on 2023-06-13; License: CC BY 4.0