.44" Miocene Mayfly (Heptageniidae) Fossil - Murat, France

This rock features a nicely preserved, .44" wide mayfly (family Heptageniidae) fossil, collected from the Upper Miocene (Messinian Stage) deposits of Murat, France. While this aquatic deposit is known for its flora fossils, it also contains a diverse insect fauna.

The rock is diatomite, a siliceous sedimentary rock composed mainly of the fossilized skeletal remains of diatoms. Due to its porous nature, it's extremely light and relatively fragile.