Phareodus

Name Meaning: Lighthouse tooth?

Geologic Era: Eocene

Location Found: Green River Formation (near Kemmerer, WY)

Range: North/South America, Australia, Europe

Size: Up to 50 centimeters in length

Extinction: 46 million years ago

This is a complete Phareodus testis fish from the Green River formation. It is about 16 centimeters long, which puts it at the smaller end for the range for this animal. As one can see, there is a large crack running diagonally through the center of the specimen. Ordinarily, this would compromise the stability of the specimen. What you can’t see is that the back has been reinforced with a wooden board, and has been glued into place. Aesthetically, perhaps not the most pleasing, but very functional.

Though Phareodus was a respectably sized fish, it was far from the biggest predator in lakes where it swam. In addition to alligators, there were several other, much larger species of fish that would have viewed Phareodus as a snack (especially one the size of our specimen). Phareodus could easily have been eaten by a large gar or Mioplosus. In terms of diet, Phareodus would have likely fed on Knightia, which was the base of the food web for many animals in the Green River lakes.