Sunday, July 31, 2011

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.