PaleoDB taxon number: 338015
Full reference: W. A. Cobban. 1988. Tarrantoceras Stephenson and related ammonoid genera from Cenomanian (Upper Cretaceous) rocks in Texas and the western interior of the United States. United States Geological Survey Professional Paper 1473:1-30
Type specimen: USNM 400773, a shell. Its type locality is USGS Mesozoic 21850, Greybull, which is in a Cenomanian marine sandstone in the Cody Shale Formation of Wyoming.
Ecology: fast-moving nektonic carnivore