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] 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.

[2][3] Helicoplacus Helicocystis Stromatocystites Titanocrinus Apektocrinus Lepidocystis Vyscystis Ridersia Gogia Argodiscus Isorophus Kailidiscus Yorkicystis Yorkicystis is a member of the edrioasteroidea, a class of echinoderms that lived by cementing themselves to hard surfaces like hardgrounds, and sometimes to living creatures like brachiopods.

[5] In the 2022 paper, researchers found Yorkicystis to form a larger clade with edrioasteroids Isorophus, Argodiscus, and Kailidiscus.