1.6" Fossil Crinoid (Abrotocrinus?) - Missouri
This is a 1.6" long (including stem) crinoid (Abrotocrinus sp.?) that was collected from the Keokuk Formation of Randolph County, Missouri. There are bryozoan fossils that have been partially exposed, scattered throughout the rock.
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.