Pantosteus

Pantosteus, the mountain suckers, is a genus of North American freshwater ray-finned fish in the family Catostomidae. Long treated as a subgenus of Catostomus, phylogenetic evidence has found them to a form a monophyletic group that diverged from other members of Catostomus during the Miocene, and they are thus treated better as a distinct genus.
They are native to mountainous regions of western North America, from southern Canada to north-central Mexico. They are primarily found in the Interior West, where they are known from the Black Hills, Rocky Mountains,parts of the Sierra Madre Occidental, much of the Great Basin, and parts of the Cascade Range. However, a single isolated species is found west of the Cascades, in the San Gabriel Mountains.
Pantosteus species tend to be smaller than those in Catostomus. They inhabit cool, fast-flowing streams located in high-elevation environments.

Taxonomy

The following species are placed in this genus:

Pantosteus bondi
Pantosteus clarkii
* P. c. intermedius
* P. c. utahensis
* P. c. "unnamed"
Pantosteus discobolus
Pantosteus jarrovii
Pantosteus jordani Barton [Warren Evermann|Evermann], 1893
Pantosteus lahontan Rutter, 1903
Pantosteus nebuliferus
Pantosteus platyrhynchus
Pantosteus plebeius
Pantosteus santaanae Snyder, 1908
Pantosteus virescens Cope, 1875

Catostomus columbianus was also previously placed in Pantosteus, and appears to have undergone some hybridization with Pantosteus in the past. However, treating it as a member of Pantosteus makes the genus Catostomus paraphyletic, and it thus continues to be treated as a member of Catostomus.
The following fossil species are also known:

†Pantosteus asitus - Early Pliocene of Nevada, US
†Pantosteus arenatus - Late Pliocene of Idaho, US
†Pantosteus hyomyzon - Middle Miocene to Late Miocene of Oregon and Washington, US
†Pantosteus oromyzon - Early Pliocene of Idaho, US