Partial Onychocrinus Crinoid From Crawfordsville

This is a partial crown of a Onychocrinus ulrichi crinoid from the famous Crawfordsville, Indiana locality. It has been microscopically prepared using air abrasives.

Crinoids are commonly known as sea lilies, though they are animals, not plants. They are echinoderms related to starfish, sea urchins, and brittle stars. They attached themselves to the sea floor and had feathery, tentacle-like appendages which they used to capture particles of food. First appearing in the Ordovician period, 488 million years ago, they still survive to this day in deep water.