Eucalyptocrinites crassus Calyx with Arms

Index fossil for the Silurian Period Waldron Shale thought to be 425 to 411 million years old. These crinoids must have flourished on the seafloor.  Judging by their root structure, the seafloor was pretty soft allowing the animal to create extensive holdfasts.  See my friend Dave's July 24, 2011 posting at Views of the Mahantango on holdfasts CLICK HERE.

This fossil is one of the best I have found with arms folded up giving the animal an egg shaped appearance.  The Eucalyptocrinites crassus (Hall, 1863) was found in Clark County.  Fossil has yet to be cleaned.

Unidentified Crinoid

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 details. Crinoid calyx was found in Indian Springs Formation of Crawford County, Indiana. This animal existed in the Mississippian Period.

It is the first Mississippian crinoid I have found with arms.

Spirifer (Delthyris) crispus simplex

This small brachiopod fossil appears to be a Spirifer (Delthyris) crispus simplex named by paleontogist James Hall in the 1800s.  Fossil was found in the Waldron Shale of Clark County, Indiana.  Dated to Middle Silurian Period (425 to 412 million years ago). A special find for me as it marks the 17th species found of identified brachiopod from the Waldron Shale.  See the others at this blog posting: CLICK HERE

Next picture is a magnified view of the growth lines on the fossil under a microscope.