Pyrite on an unidentified crinoid stem from the Waldron Shale of Clark County Indiana, USA.  Crinoid lived in the Silurian Period.

An Eucalyptocrinites crinoid calyx cup found in the Waldron Shale of Clark County, Indiana.  My first mostly intact Silurian Period crinoid...

Aulopora schoharie coral fossil of the Birdsong Formation found in Benton County, Tennessee.  It lived in the Lower Devonian Period.  Tha...