Caryocrinites cystoid fossil found in the Waldron Shale of Clark County, Indiana.  Animal dates to Middle Silurian Period.  This anim...

Index fossil for the Silurian Period Waldron Shale thought to be 425 to 411 million years old. These crinoids must have flourished on the...

Here is a crinoid calyx with arms and an imprint where the stem was.  The fossil needs to be air abrasive cleaned to reveal more of its d...