5.4" Plate Of Crinoids (Pentacrinites) - North Whitby, England
This is a plate of rare Pentacrinites crinoids from Port Mulgrave, North Whitby, England. There are two mostly complete crinoids on one side of this piece with crowns and stem sections. There is a third crown on the back side of the piece as well as the rock being full of crinoid pieces.
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.