Stingrays
Heliobatis radians
One of two freshwater stingray species known from the Fossil Butte Member.
Stingrays
Asterotrygon maloneyi
A Fossil Lake stingray known from embryos through adults, including specimens with young nearby.
Paddlefish
Crossopholis magnicaudatus
A predatory paddlefish often preserved with fish in its stomach.
Gars
Lepisosteus bemisi
A long-snouted Fossil Lake gar with needle-like teeth and extra tail fin rays.
Gars
Atractosteus simplex
A Fossil Lake gar armored in tough diamond-shaped scales.
Gars
Atractosteus atrox
The largest Green River Formation gar species.
Gars
Masillosteus janei
An unusual Fossil Lake gar with rounded crushing teeth instead of a long toothy snout.
Bowfins
Cyclurus gurleyi
An extinct bowfin relative with crushing jaws suited to invertebrates.
Bowfins
Amia pattersoni
A Fossil Lake bowfin with a long jaw and pointed teeth — a possible apex predator.
Ray-finned Fish
Diplomystus dentatus
The second-most common Fossil Lake fish — a primitive herring relative with an upturned mouth.
Herrings
Knightia eocaena
Wyoming's state fossil and the most common articulated vertebrate fossil in the world.
Herrings
Knightia alta
A schooling Fossil Lake herring often found in mass mortality plates.
Beaked Sandfish
Notogoneus osculus
A migratory bottom-feeder and the last North American survivor of its order.
Perches
Mioplosus labracoides
A Fossil Lake perch that schooled as a juvenile and hunted alone as an adult.
Perches
Cockerellites liops
A small schooling perch — the fish featured on Fossil Butte's entrance sign.
Perches
Priscacara serrata
A larger perch with crushing teeth that did not school like C. liops.
Perches
Hypsiprisca hypsacantha
Originally described as Priscacara hypsacantha by Cope.
Perches
Hypsiprisca sp.
A slender Hypsiprisca with a more convex tail fin margin than H. hypsacantha.
Mystery Fish
Asineops squamifrons
The classic “mystery fish” — hard to place in any living order.
Mystery Fish
Asineops sp.
A second mystery-fish species assigned to the family Asineopidae.
Bony-Tongue Fish
Phareodus encaustus
A predatory bony-tongue fish that schooled young and hunted alone as an adult.
Bony-Tongue Fish
Phareodus testis
A smaller Phareodus predator from Fossil Lake.
Trout-Perch
Amphiplaga brachyptera
The earliest known trout-perch, known only from Fossil Lake deposits.
Mooneye
Hiodon falcatus
A near-shore Fossil Lake mooneye related to living North American Hiodon species.
Pikes and Pickerels
Esox kronneri
Known from only a single specimen — possibly a stream-dwelling pike.