These fossil fish are Knightia sp. and are from Wyoming, USA . They are 57-35 million years old, making them from the Eocene epoch. The fossils themselves are very fragile, which is why they're in a frame.

The very first fish evolved during the Cambrian period, over 530 million years ago. One of the first fish was known as Haikouichthys, and was the first backboned creature, and the ancestor of all vertebrates.