Currently there are believed to be four species of Leptosuchus. All species share in common a similar position of the temporal arch below the skull roof and a posterior process of the squamosal that extends farther than the paroccipital process.[2] The type species is L. crosbiensis, which was named in 1922 on the basis of material found from Texas.[3] L. adamanensis was first described in 1930 as a species of Machaeroprosopus from the Blue Mesa Member of Petrified Forest National Park, along with the other two species, L. lithodendrorum and L. gregorii. It was not until the publication of a 1995 paper on tetrapods of southwestern United States that these species were recognized as belonging to the genus Leptosuchus. However, because of the distinctive size of the rostral crest in L. grego