2.4" Unusual Crinoid (Forbesiocrinus) - Crawfordsville, Indiana

Unusual Crinoid (Forbesiocrinus) - Crawfordsville, Indiana #110594

This is a large, 2.4" fossil crinoid from the Edwardsville Formation, Crawfordsville, Indiana. This specimen is Forbesiocrinus and contains the stem, calyx, and feeding arms. There is one repaired crack running through the rock and the specimen. This is a rarely seen crinoid from the formation and a beautiful specimen.

The quality of preparation on this fossil is exquisite - using skillful air-abrasion techniques under a stereo microscope.

Crinoids from the Ramp Creek Limestone were likely 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