Crinoids are commonly known as sea lilies, although 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.
Crawfordsville, Indiana is renowned for producing some of the most spectacular crinoid fossils in the world. There are more than 60 different species known from the Lower Mississippian (~340 million year old) Edwardsville Formation. These crinoids when properly prepared are preserved in beautiful, three dimensional relief against the surrounding matrix.