Macrocrinus Crinoid With Preserved Anal Tube

This is a 2.8" Macrocrinus mundulus 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. While most of the arms of the crinoid are either missing or buried in the matrix is displays a very well preserved anal tube coming out of the crown which is unusual.

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.

Note: This crinoid was remounted on a piece of limestone for aesthetic display purposes.