Fossil Sardine Fish

This is a fossil fish called a Knightia alta that probably came from Middle Eocene epoch.  I have one just like it and it came from Lincoln County, Wyoming from the Green River Shale.  It is definitely a prehistoric fish.  The Green River Shale is one of the best places in the world to find the Knightia alta.

These fish are permanently embedded into the formation they are found on.  They are very small and were probably like our modern-day sardines.