''Belantsea'' (named after a legendary ancestor of the

Crow Nation The Crow, whose Exonym and endonym, autonym is Apsáalooke (), also spelled Absaroka, are Native Americans in the United States, Native Americans living primarily in southern Montana. Today, the Crow people have a federally recognized tribe, th ...

) is a genus of extinct petalodontid

cartilaginous fish Chondrichthyes (; ) is a class that contains the cartilaginous fishes that have skeletons primarily composed of cartilage. They can be contrasted with the Osteichthyes or ''bony fishes'', which have skeletons primarily composed of bone tissue ...

that lived during the Lower

Carboniferous The Carboniferous ( ) is a geologic period and system of the Paleozoic that spans 60 million years from the end of the Devonian Period million years ago ( Mya), to the beginning of the Permian Period, million years ago. The name ''Carbonifero ...

, about 350 million years ago. Its fossils are found in the

Bear Gulch Limestone The Bear Gulch Limestone is a limestone-rich geological lens in central Montana, renowned for the quality of its late Mississippian-aged fossils. It is exposed over a number of outcrops northeast of the Big Snowy Mountains, and is often considere ...

lagerstätte A Lagerstätte (, from ''Lager'' 'storage, lair' '' Stätte'' 'place'; plural ''Lagerstätten'') is a sedimentary deposit that exhibits extraordinary fossils with exceptional preservation—sometimes including preserved soft tissues. These for ...

. Its body was leaf-shaped, with muscular fins and a small tail. Such a

body plan A body plan, ( ), or ground plan is a set of morphological features common to many members of a phylum of animals. The vertebrates share one body plan, while invertebrates have many. This term, usually applied to animals, envisages a "blueprin ...

would allow for great maneuverability, but at the cost of speedy cruising. Its few, large, triangular teeth formed a beak-like arrangement that allowed it to graze bryozoans, sponges, crinoids, and other encrusting animals. The genus contains two species, ''B. montana'' and ''B. occidentalis''. ''Belantsea'' is the best known member of the

order Order, ORDER or Orders may refer to: * Categorization, the process in which ideas and objects are recognized, differentiated, and understood * Heterarchy, a system of organization wherein the elements have the potential to be ranked a number of d ...

Petalodontiformes Petalodontiformes ("thin-plate teeth") is an extinct order of marine cartilaginous fish related to modern day chimaera found in what is now the United States of America and Europe.Lund, Richard, E. D. Grogan, and M. Fath. "On the relationships ...

References

External links

Bear Gulch
Petalodontiformes Mississippian fish of North America Fossils of the United States Prehistoric cartilaginous fish genera Fossil taxa described in 1989 {{paleo-cartilaginous-fish-stub