Two Fossil Crinoids (Agaricocrinus & Cyathocrinites) - Indiana

These are two fossil crinoids from the Edwardsville Formation crinoid beds near Crawfordsville, Indiana. This association includes a large 1.7" long Agaricocrinus americanus crinoid crown and what appears to be two partial crinoids of the species Cyathocrinites iowensis. These fossils were prepared using skillful air-abrasion techniques under a stereo microscope.

The largest crinoid (Agaricocrinus americanus) appears to have been removed from the rock, prepped and then remounted in the same location. The Cyathocrinites crinoid(s) appear to have undergone the same process. It comes with an acrylic display stand.

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