Sponge Fossil from Wheeler Shale

Description: Coming from the Cambrian Wheeler Formation deposits of Millard County, Utah, this plate contains a sponge known as Choia carteri. Choia are members of Class Desmospongia, Family Choiidae. Choia lived on the seafloor unattached and filtered food particles from the water. Choia carteri is more rare than Choia utahensis, an uncommon fossil in its own right.

Sponge fossils from the Cambrian Explosion are found in various Cambrian sites in North America, most notably the Burgess Shale of Canada, and the Cambrian strata of Utah, like this specimen. Many sponges are also described from the Chengjiang biota of China. Sponges are believed to have undergone repeated radiations in the Phanerozoic, and probably attained their greatest diversity in the Cretaceous.