Yorkicystis
From Wikipedia, the free encyclopedia
| Yorkicystis Temporal range: Cambrian, | |
|---|---|
Scientific classification  | |
| Kingdom: | Animalia |
| Phylum: | Echinodermata |
| Class: | †Edrioasteroidea |
| Genus: | †Yorkicystis Zamora et al., 2022 |
| Type species | |
| †Yorkicystis haefneri Zamora et al., 2022 | |
Yorkicystis is a genus of edrioasteroid echinoderm that lived 510 million years ago in the Cambrian aged Kinzers Formation in what is now Pennsylvania.[1] This genus is important as it provides some of the oldest evidence of echinoderms losing their hard mineralized outer skeletons.[1] Yorkicystis also shows that some echinoderms lost their skeletons during the Cambrian, which is a greatly different time as to when most other species lost theirs.[1]
Fossils of this genus were first discovered in May 2017 by Christopher Haefner in a churchyard in York, Pennsylvania in shale deposits in the Emigsville Member of the Kinzers Formation.[1] Two specimens were found, and numbered NHMUK EE 1659-1660.[1] Aside from Yorkicystis other echinoderms like Lepidocystis and Camptostroma have been found in the formation.[1] The species name is in honor of Haefner, who discovered the fossils,[1] and the genus name is derived from the town of York.[1]
Description
Yorkicystis is unique because it has a non-mineralized skeleton.[2] Most echinoderm groups around today like starfish and sea urchins have a mineralized skeleton, and others like derived crinoids and holothurians (sea cucumbers) have one, but it is greatly reduced.[2][3]
