A large fossil fish plate.
Knightia are the most common fish found in the Green River Formation, Wyoming. An Eocene geological formation in the Rocky Mountains.These are limestone fossils and vary in colour from light brown to dark brown.
A fish is any aquatic vertebrate animal that is covered with scales and equipped with two sets of paired fins and several unpaired fins. Most fish are cold-blooded or ectothermic allowing their body temperatures to vary as ambient temperatures change. Fish are abundant in most bodies of water. They can be found in nearly all aquatic environments from high mountain streams to depths of the deepest oceans.