Lot 10 Pcs Fossil Sponges Sea Porifera Calcarea Spongia Paleozoic Carboniferous Collection

Lot of 10 Fossil Marine Sponges mixed species mm 10-23 gr 4.3 Benthic Invertebrata Sessile Porifera Limestone Prehistoric Extinct Paleozoic Carboniferous Collecting Paleontology Museum.

Interesting fossil finds of specimens of Porifera Spongia Calcarea from the Pennsylvanian (Upper Carboniferous) of Texas (USA), representative collectible specimen of excellent quality and well preserved, with evident surface details of the colonial limestone structure of the calcium carbonate Skeleton. Single lot, as in the photo.

The lot contains a few genera represented of Phylum Porifera from the Grayford Formation of Texas, including Girtyocoelia, Coeolocladia, Heterocelia, Amblisiphonella, etc. A rare sample, collected almost 40 years ago and the locality is long closed.  It is a great opportunity to get some nice Pennsylvanian sponges suitable for study, sectioning and display.

The calcareous Sponges of the Calcarea class are members of the animal phylum Porifera (Nuda or Spongia), the cellular sponges. They are characterized by spicules consisting of calcium carbonate in the form of calcite or aragonite. All the sponges of this class, divided into two subclasses and seven orders, are strictly marine, most of which are found in shallow tropical waters and are distributed all over the world. Like all other sponges, they are sedentary filter feeders. Typically, the calcareous sponges are small, measure less than 10 cm in height and are dark in color. However, some brightly colored species are also known.
The calcareous sponges vary in shape from types with radially symmetrical vessel bodies to colonies consisting of a lattice of thin tubes or massive irregular shapes. The skeleton has a mesh or honeycomb structure. Of the 15,000 existing Porifera species, only 400 of these are in the Calcarea class.
The calcareous sponges appeared for the first time during the Cambrian period and their diversity was greater during the Cretaceous period. Recent molecular analyzes suggest that the Calcarea class should be designated as a phylum, in particular the first that, diversifying, originated the Animalia kingdom; the other sponges belong to the phylum Silicarea, that is the sponges with silicon skeleton. Half of the documented species of Porifera are fossil and extinct.