Cambrian Explosion Fossil Sponges
sp. (Kingdom: Animalia;
Phylum: Porifera; Class:
Demospongia; Subclass: Ceractinomorpha; Family: Hazeliidae; Genus: Crumillospongia)
Cambrian Utah Cambrian Explosion
inch): Matrix 4" X 6" (105mm X 154mm) Largest sponge 7/8"
Marjum Formaion, Millard County, Utah
Demosponge Crumillospongia belong to the family Hazeliidae. Because
no attachment structures have ever been found, so it remains unclear
whether or not this early Profera lived attached to the seafloor.
Crumillospongia are somewhat rare in the Middle Cambrian of utah,
and very rare in the Burgess The Crumillospongia sponges on this
plate have unusually good contrast.
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 largest
diversity in the Cretaceous.