Here is a well detailed Large Holocystites Cystoid an extinct echinoderm – relatives of the modern starfish. They were attached to the bottom of the sea floor by means of a short stalk.
Cystoid means “sac-like” referring to the portion of the creature called a theca. The theca is the main body and sits atop a column of round disk-shaped segments. A theca is comprised of a generally oval shaped body made up of geometric or plates. It contains all the internal organs as well as the mouth and anus.
This Large Holocystites Cystoid lived on the ancient ocean floor. This is a theca. Attached to the theca, the arms can be found. But in some exquisitely preserved specimens the food capturing parts are found well preserved. They were covered with small “tube feet” that would capture food particles as they floated by. Their food was plankton and any matter that happened by. The food would be moved towards the mouth and passed inside. This was repeated over and over as food contacted the “tube feet”. The digestive system would process these and then waste matter would be ejected.
Due to this Large Holocystites Cystoid hard outside skeleton it exhibits great detail. This is especially true with the complete fossils from here.
Cystoids can be found in various numbers in locations and formations around the United States and the world. Generally they are found in sediments dating to the Middle Ordovician Period, some 460 million years ago, to the end of the Devonian Period some 358 million years ago.
Specimen was meticulously prepared using micro air abrasive technology. The cystoid is 1 1/4 inch long by 7/8 inch wide.