''Heteropetalus'' is a genus of chondrichthyan from the

Mississippian age The Mississippian ( ), also known as Lower Carboniferous or Early Carboniferous, is a subperiod in the geologic timescale or a subsystem of the geologic record. It is the earlier of two subperiods of the Carboniferous period lasting from rou ...

Bear Gulch Limestone The Bear Gulch Limestone is a limestone-rich Lens (geology), geological lens in central Montana, renowned for the quality of its marine fossils from the late Mississippian (geology), Mississippian subperiod, about 324 million years ago. It is expo ...

of Montana,

United States The United States of America (USA), also known as the United States (U.S.) or America, is a country primarily located in North America. It is a federal republic of 50 U.S. state, states and a federal capital district, Washington, D.C. The 48 ...

. One species, ''H. elegantulus'', is known. Known fossils of ''Heteropetalus'' are exceptionally well preserved, displaying details of the soft tissue anatomy such as an opercular cover over the gills.

References

Holocephali Prehistoric cartilaginous fish genera Prehistoric cartilaginous fish stubs Mississippian animals {{Paleo-cartilaginous-fish-stub