Fish Fossils

Did you know that fish are the world's oldest known vertebrates? Perhaps the most widely recognized form of fish fossil is the shark's tooth, but in general, fish fossils are very common in the fossil record. While a significant number of specimens have been found in Southern Wyoming's Green River Formation, fossil fish have been discovered on every continent.

Fish Fossils: Record of the Oldest Vertebrates

Wyoming fish fossils were first discovered on the banks of the Green River. As more and more fossils were excavated, it was soon realized that this river held the richest deposit of fossil fish on record. The Green River Formation actually includes an area that covers hundreds of miles across Wyoming, Utah and Colorado. Scientists continue to excavate and study this area to gain a better understanding of the evolution of fish.

Fish have flourished throughout evolution. In fact, if you combined all the vertebrate species alive today, it would not number as many as the species of bony fish in today's rivers, lakes and oceans. Most fossil fish have features that appear very similar to today's modern fish, including gill slits and a backbone. Early fish fossil records demonstrate how these primitive creatures evolved into our modern fish, developing jaws and an outer covering or "skin."

Fossil fish are highly collectible and can represent excellent investments, both for their scientific value and their beauty. The rarest types of fossil fish include the mooneye, paddlefish, gar, dogfish, and the sand fish or suckerfish. These rare fish can be found in limited numbers in the Green River Formation.