Interesting 2.3" Gilbertsocrinus Crinoid - Indiana

This is a 2.3" wide Gilbertsocrinus dispansus crinoid fossil 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.

It is believed that crinoids from the Edwardsville Formation 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.