1.7" Cactocrinus Crinoid Calyx - Burlington Formation, Missouri
This is a 1.7" crinoid (Cactocrinus glans) Calyx from the Burlington Formation of Missouri. It has been prepared with air abrasives and comes with an acrylic display stand.
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.