Five Species of Crinoids on One Plate - Crawfordsville, Indiana

These are five fossil crinoids from the Edwardsville Formation crinoid beds near Crawfordsville, Indiana. This association includes a Hypselocrinus hoveyi crinoid (#32), a Sarocrinus granilineus (#41), a Macrocrinus mundulus crinoid (#69), a Onychocrinus ulrichi crinoid (#81) and a Hylodecrinus briareus crinoid (#101).

These fossils were prepared using skillful air-abrasion techniques under a stereo microscope. It comes with an acrylic display stand.

#32 - Hypselocrinus hoveyi
#41 - Sarocrinus granilineus
#69 - Macrocrinus mundulus
#81 - Onychocrinus ulrichi
#101 - Hylodecrinus briareus

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