1.7" Fossil Crinoid (Jimbacrinus) - Gascoyne Junction, Australia
This is 1.7" long, alien-looking, fossil crinoid (Jimbacrinus bostocki) from the Cundlego Formation near Gascoyne Junction, Australia. It has been prepped to expose the calyx (body) and pinnules (feeding arms). It has remarkably detailed 3D preservation.
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.