Wednesday, July 9, 2008

Flexicalymene or Calymene Trilobite

This blog is to highlight fossils found around Louisville, Kentucky and southern Indiana. So to start it off I found a fossil while cycling this morning on the side of the road. Usually, the trilobite is one of the hardest to find. For those who do not know, a trilobite is a completely extinct creature that is an arthropod. Arthropods are spiders and crabs today. The trilobite might be closest related to the horseshoe crab of today.

I was surprised to see this fragment in the gravel spot in the grass. Since it was in a mix of gravel it is hard to say if it weathered out the ground or was dropped there. The rock seems almost like sandstone and the fossil is an imprint. I am wondering if it is Silurian period but it could be Devonian.

Usually, I find Phacops trilobites in this area and a lot of times I just find part of the tail section. So this is nice to find an almost intact head and enough of it to see it matches narrow nose with small eyes and a bump in front of each eye.

After researching another trilobite, this appears to be Silurian in age. The question is now is it a Calymene celebra shown at the Kentucky Paleontological Society webpage link or a "Flexicalymene" celebra shown on page 108-109 figure 1 in the Fossils of Ohio book (1996, Ohio Department of Natural Resources, Bulletin 70).