Protospongia Fossil Sponge from Utah

Protospongia hicksi belongs to the family Protospongiidae, which was a group of early and primitive sponges of the Class Hexactinellida. It was a stalkless sponge that was attached to the sea floor by long spines at the base of the sponge. These spines are rarely preserved. The cruciform spicules are quite diagnoistic; based upon the size of the largest of the preserved examples, this one would have been at least 100 mm in height. Sponges are relatively uncommon in the fossil record owing to their delicacy. This specimen exhibits unusually fine preservation .