Fossil of Cothurnocystis elizae （圖片來源：Dwergenpaartje，採用  CC BY-SA 3.0  授權） Age Ordovician（Tremadocian-Floian） 480-475 Ma Taxonomy Kingdom: Animalia Phylum: Echinodermata Class: Stylophora Order: Cornuta Family: Cothurnocystidae Genus: Cothurnocystis Species: Cothurnocystis elizae Morphological description Cothurnocystis elizae  possesses a disproportionately large, head-like structure covered with numerous small plate-like elements. This structure bears a row of small opening