Species: coloradensis SIMPSON, 1927
Etymology: In reference to the state of Colorado, where the specimen was found.

Holotype: USNM 2723

Locality: Garden Park, near Canyon City, Colorado.

Horizon: Member? Morrison Formation.

Biostratigraphy: Zone?

Age: Age?, Stage?, Malm Epoch, Late Jurassic.

Material: Right lower jaw in matrix, inner aspect, with p4 and m1-8, somewhat broken.

Referred material:

Numbers: Not given: 2 lower jaws.