Macrocrinus Crinoid Fossil With Unidentified Holdfast

This is a cool crinoid plate from collected from the Witherspoon Quarry near Crawfordsville, Indiana. There are two crowns of a Macrocrinus mundulus crinoid associated with a holdfast of another unidentified crinoid fossil. The quality of preparation on this fossil is exquisite - using skillful air-abrasion techniques under a stereo microscope.

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.