Genus Priscacara is perhaps the most popular of the Green River Formation fish fossils. A member of the Family Priscacaridae, the name Priscacara means "primitive head". Shaped rather like a sunfish, the genus sports sturdy, protective dorsal and anal spines. Among the two species, liops and serrata, serrata is uncommon. Liops is the smaller species, never exceeding 150 mm, whereas serrata have been found up to 375 mm.