Detailed Halysiocrinus Crinoid Fossil - Crawfordsville

This is a beautifully detailed Crinoid fossil of the species Halysiocrinus tunicatus from Crawfordsville, Indiana. The crown is 1.8" long and there is a section of stem folded over laying next to the crown. This specimen has been microscopically prepared using air abrasives and ID'd by one of the best preparators out there who'd done a ton of work on the Crawfordsville crinoids.

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.