6.6" Crinoid Plate - Crawfordsville, Indiana

Crinoid Plate - Crawfordsville, Indiana #69479

This is a Macrocrinus mundulus and two Barycrinus stellatus crinoids from the famous Witherspoon crinoid quarry near Crawfordsville, Indiana. The two Barycrinus crinoids are located adjacent to each other, with the Macrocrinus off to the side. They have been prepared under microscope using air abrasives.

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.

Crinoids, sometimes commonly referred to as sea lilies, are animals, not plants. They are echinoderms related to starfish, sea urchins, and brittle stars. Many crinoid traits are like other members of their phylum; such traits include tube feet, radial symmetry, a water vascular system, and appendages in multiples of five (pentameral). They first appeared in the Ordovician (488 million years ago) and some species are still alive today.

About Crinoids