Phragmoceras is a rare fossil that I found in the Osgood shale. It's a nautiloid (cephalopod ) that has a slightly curved shell. The fossil I found is only a partial but the shell decoration is still evident.
This specimen was found near Napoleon, IN and is from rocks deposited during the Silurian (Telychian to Sheinwoodian stage).
My friend Nathan found a larger and more complete specimen of Phragmoceras in his local Racine formation of Wisconsin.