What is "priscacara"

Priscacara is an extinct genus of perch from the middle Eocene. It is characterized by a sunfish-like body and its stout dorsal and anal spines. The fish is best known from the Green River Shales of Wyoming, Utah and Colorado. Mass deaths of Priscacara suggest it formed schools[1].

Two species are recognized, of which the smaller species, P. liops is the most common. Priscacara fossils are common in the Fossil Lake deposits of western-most Wyoming and is rare in the Lake Gossiute deposits of Wyoming and the Lake Uinta deposits of Utah and Colorado[1]. It also occurs in the middle Eocene lake deposits of Washington and British Columbia[1].

A phylogenetic review of Priscacara by Whitock[2], found only two species, P. serrata and P. liops. The two species differ in the number of dorsal and anal fin rays, as well as possibly a coarser serrated rear edge of the preopercle in P. serrata[2],. P. liops also has small conical teeth on the pharyngeal jaw, whereas P. serrata has large grinding toothplates[2], suggesting a diet of snails and crustaceans[1].