6.8" Crawfordsville Crinoid Association - Crawfordsville, Indiana

This is a nice association of four different species of crinoids from the Ramp Creek Limestone. There are two types of Cyathocrinites, a Barycrinus and an Onychocrinus. It was collected from the famous Witherspoon Quarry near Crawfordsville, Indiana and prepared under microscope.

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.