Crinoids (Tholeocrinus) and Blastoid (Pentremites) - Kentucky

This is a wonderfully preserved pair of Tholeocrinus spinosis crinoids from the Glen Dean Formation near Grayson County, Kentucky. The matrix measures 4.3x3.5" with the largest crinoid measuring just over 1" in length. It meticulously prepared under microscope using air abrasives to expose the superb surface detail of the fossils. A blastoid of the genus Pentrimites, can also be found partially exposed from the crinoid stem and Bryozoa littered rock.

While the blastoid and one of the crinoids are definitely in their natural resting location within the rock, the other crinoid looks to have been prepped entirely, to later be remounted onto the rock. It's very possible that it came from this same spot in the rock, however there is no way to ensure this.

Crinoids are commonly known as sea lilies, though they are animals, not plants. They are echinoderms related to starfish, sea urchins, and brittle stars. They attached themselves to the sea floor and had feathery, tentacle-like appendages which they used to capture particles of food. First appearing in the Ordovician period, 488 million years ago, they still survive to this day in deep water.