Species: oweni SIMPSON, 1927
Etymology: In honor of Richard Owen.
Holotype: YPM 10663
Locality: Reeds YPM Quarry 9, (Mammal Quarry), T22N, R77W, Sec. 12, Como Bluff, Albany County, Wyoming.
Horizon: Brushy Basin Member, Morrison Formation.
Biostratigraphy: Zone 3.
Age: Upper Part, Comobluffian age, Kimmeridgian Stage, uppermost Malm Epoch, Late Jurassic.
Material: Part of right maxilla with P4 and M1-5.
Referred material:
YPM 13752: Maxilla fragment of UM1-2.
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Species: osborni SIMPSON, 1927
Etymology: In honor of Henery Osborn.
= Malthacolestes osborni SIMPSON, 1927
Holotype: YPM 13751
Locality: Reeds YPM Quarry 9, (Mammal Quarry), T22N, R77W, Sec. 12, Como Bluff, Albany County, Wyoming.
Horizon: Brushy Basin Member, Morrison Formation.
Biostratigraphy: Zone 3.
Age: Upper Part, Comobluffian age, Kimmeridgian Stage, uppermost Malm Epoch, Late Jurassic.
Material: Part of right maxilla with M1-2.
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Species: grandis (SIMPSON, 1929)
Etymology:
Holotype: YPM 13727
Locality: Reeds YPM Quarry 9, (Mammal Quarry), T22N, R77W, Sec. 12, Como Bluff, Albany County, Wyoming.
Horizon: Brushy Basin Member, Morrison Formation.
Biostratigraphy: Zone 3.
Age: Upper Part, Comobluffian age, Kimmeridgian Stage, uppermost Malm Epoch, Late Jurassic.
Material: Part of a right lower jaw with m1-4 broken.