Fossil range: Lower Carboniferous
Reconstruction of the Lower Carboniferous cartilaginous fish, Belantsea montana, from what is now Bear Gulch, Montana.
| Scientific classification
Belantsea montana (named after a legendary ancestor of the Crow Nation) was a peculiar-looking cartilaginous fish that lived during the Lower Carboniferous. Its fossils are found in the Bear Gulch Limestone lagerstätte. Its body was oddly built, being leaf-shaped, with muscular fins and a small tail.
Belantsea had a bodyplan that 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.
B. montana is the best known of a group of bizarre cartilaginous fish known as the "Petalodontiformes".