Species: montanus (MARSH, 1877) MARSH, 1877
Etymology: In reference to the eastern flanks of the Rocky Mountains.
= Titanosaurus montanus MARSH, 1877
= Brontosaurus montanus (MARSH, 1877) KUHN, 1965
Holotype: YPM 1835
Locality: Lakes' YPM Quarry 1, T. 4S., R70W, Sec. 26, Jefferson County, Colorado.
Horizon: Member? Morrison Formation.
Biostratigraphy: Zone?
Age: Age?, Stage?, Malm Epoch, Late Jurassic.
Material: Fragmentary sacrum.