Macrocrinus & Platycrinites Crinoids - Crawfordsville, Indiana

This is a pair of wonderfully preserved crinoid fossils from Crawfordsville, Indiana. There is a Macrocrinus mundulus with a partial stem and anal tube preserved on top of the crown of a Platycrinites. The crown of Macrocrinus is 1.4" long. They been been cleaned under microscope using air abrasives. The stem of the Macrocrinus maybe a composite.

It is believed that crinoids from the Ramp Creek Limestone were buried in sediment from nearby deltas during storms. The resulting siltstone deposits are soft enough that fossils can be extracted in exquisite, three-dimensional relief.