50 million year old old fossil fish

45-50 million-year-old fossil

These fish are between 45 and 50 million years old and come from the Wyoming region in the USA. In the Eocene, there was a huge lake with a lot of fish in it. Due to rainy periods and dry periods, a layer of sediment was added to the bottom of the lake each year. Six million years of continuous sediment have been found.

Fossilized fish

Between the sediment fish, but sometimes also other animals, could be preserved. Because of the sedimentary barrier the carcass could not decompose and it had the chance to fossilize. Wyoming is known for its great diversity of fossils and the high quality in which they are preserved.