Euthlastus is an extinct genus of Late Jurassic (Kimmeridgian - Tithonian) mammal from the Morrison Formation. Present in stratigraphic zones 5 and 6.Foster, J. (2007). "Appendix." Jurassic West: The Dinosaurs of the Morrison Formation and Their World. Indiana University Press. pp. 327-329. It is represented by only five upper molars.G. G. Simpson. 1927. Mesozoic Mammalia. VI. Genera of Morrison pantotheres. American Journal of Science 13:409-416.
See also
Prehistoric mammal List of prehistoric mammals Paleobiota of the Morrison Formation
References
Foster, J. (2007). Jurassic West: The Dinosaurs of the Morrison Formation and Their World. Indiana University Press. 389pp.