Crinoid slice, crinoid stem cut by Gary WilsonCrinoid Earrings
Everyone loves crinoids, don't you?! Show your love by wearing these teensy fossil earrings! The post on the left has a slice from a crinoid stem. The central axial canal or lumen contained a fluid-filled sac and nerve. Different types of crinoids have differently-shaped lumens, some are circular, some have 5-ponted stars, and some the little four or five-petaled flower shape of our example. The dangle earring on the right takes up the flower-on-top-of-a-stem theme in sterling and fossil crinoid stem. Wiki says that the largest fossil crinoid stem found is 40 m (130') long! The segments are clearly evident even in this tiny stem. Sometimes these segments separate in the fossil record as the connective tissue holding them together decays, yielding St. Cuthbert's beads, called by many names including fairy money, St. Boniface's pennies, Indian beads, etc.
Crinoids are marine echinoderms, a phylum of organisms having pentaradial symmetry. What is incredibly peculiar about them is that they are standing on their heads compared to other echinoderms. Their supporting stalk forms on the aboral surface which forms the upper side of creatures such as starfish. How do we know this? There are presently still about 600 living species of crinoids compared to almost unimaginable diversity before they endured a selective mass extinction at the end of the Permian possibly due to predation. Other stalked filter-feeding echinoderms such as blastoids didn't fare as well and none survived the mass extinction. It's a cautionary tale for other top predators to consider don't you think?
You will be tested on crinoid ontogeny and natural history. Wouldn't you like to have these earrings to see you through? Please order today and enjoy telling their amazing story.
