Paleoniscoid-Montana-BG056

Taxa: Indeterminate paleoniscoid

Age: Carboniferous-Mississippian

Geology: Heath Limestone-Bear Gulch Member

Locality: Fergus County, Montana

Paleoniscoids

Paleoniscoids are an extinct group of primitive ray-finned fishes (Actinopterygii) that lived from the Late Silurian to the Late Triassic periods. They are characterized by their elongated bodies, large, rhombic, and heavily ganoid scales, and heterocercal tails, where the upper lobe is longer than the lower. Their skulls were typically bony, with a jaw structure indicating a powerful bite. Paleoniscoids were among the earliest examples of ray-finned fishes and played a crucial role in the evolutionary history of modern fishes. They were primarily freshwater species but were also found in marine environments.

Bear Gulch

The Bear Gulch Limestone is a fossil-rich geological formation located in Montana, USA, known for its exceptional preservation of marine fossils from the Mississippian subperiod of the Carboniferous period, approximately 330 million years ago. Use the hyperlinked text to learn more!