The other is the original type species: "O. velox", at first known from very limited remains. Additional specimens referred to "O. velox" have been described from the Denver Formation and from the Ferris Formation of Wyoming. One specimen attributed to "O. velox" (MNA P1 1762A) from the Kaiparowits Formation of Utah, was described in 1985. Re-evaluation of this specimen by Lindsay Zanno and colleagues in 2010, however, cast doubt on its assignment to "O. velox", and possibly even to "Ornithomimus". This conclusion was supported by a 2015 re-description of "O. velox", which found that only the holotype specimen was confidently referable to that species. The authors of this study tentatively referred to the Kaiparowits specimen as "Ornithomimus sp.", along with all of the specimens from the Dinosaur Park Formation.