.4" Miocene Spleenwort (Asplenium) Fossil - Murat, France

This rock features an incredibly well preserved, .4" wide spleenwort (Asplenium viride) fossil, collected from the Upper Miocene (Messinian Stage) deposits of Murat, France. The plants around this aquatic deposit would often drop various flora pieces into the water to be preserved alongside other aquatic fossils.

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.