Pachyiocrinus & Onychocrinus Crinoids - Crawfordsville, Indiana

This is a pair of detailed crinoid fossils from the famous Witherspoon crinoid quarry near Crawfordsville, Indiana. The quality of preparation on this fossil is exquisite - using skillful air-abrasion techniques under a stereo microscope. The larger crinoid is a Pachyiocrinus aequalis and the smaller specimen is Onychocrinus ulrichi. There is some repair work done to the surrounding matrix.

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.