Sponges
Sponges belong to the phylum Porifera. Sponges are primitive multicellular animals, living attached to the seafloor. They filter the seawater to extract foodparticles. In some sponges you can sea the wastewater opening where the filtered water was discharched.
Most sponges have a skeleton that consists of small skeletal parts (specula) made of spongine, chalk or silica. The taxonomy of the sponges is based on the type of skeleton: Spongine sponges (Demospongiae), Chalksponges (Calcispongiae) and silica sponges (Hexactinellida). Sponges with a silica skeleton fossilize easily. Especially in Cretaceous  deposits, sponges are abundant. The oldest known sponges are from the Precambrian period.
Example of a sponge from Paulmy, France.
 Click here for information where to find these fossils.
 Go to the Photo page to view photographs of Sponges. |
