Diplomystus Fossil Fish Plate

Approximately 48 million years old Diplomystus was a herring-like fish that lived in the early Eocene (roughly 48 million years ago) and was prolific in freshwater environments the world round. They are usually found in the Green River Formation (more on that later) and are really impressive fossil specimens. The detailing of the ribs down to the fins is really something to take in. It’s still crazy to us that something that lived so long ago is right in front of us in vivid detail. While it’s a very pretty specimen, Diplomystus was a fierce little fish. Diplomystus is an extinct genus of freshwater, ray-finned predators. It had a distinctive jaw that protruded aggressively outward from the mouth at an angle that allowed it to feed in surface waters and devour such prey as the smaller Knightia fish. The fossils above were small but mighty fish although some fossils show it could reach up to 20 inches long!  These fossil fish provide an interesting look into our earth’s ancient past. Th