Archaeocyatha is a taxon of extinct, sessile, reef-building marine organisms of warm tropical and subtropical waters that lived during the early (lower) Cambrian Period. It is believed that the centre of the Archaeocyatha origin are now located in East Siberia, where they are first known from the beginning of the Tommotian Age of the Cambrian, 525 million years ago (mya). In other regions of the world, they appeared much later, during the Atdabanian, and quickly diversified into over a hundred families. They became the planet's very first reef-building animals and are an index fossil for the Lower Cambrian worldwide.
Hexactinellid sponges are sponges with a skeleton made of four- and/or six-pointed siliceous spicules, often referred to as glass sponges. They are usually classified along with other sponges in the phylum Porifera, but some researchers consider them sufficiently distinct to deserve their own phylum, Symplasma.
The calcareous sponges of class Calcarea are members of the animal phylum Porifera, the cellular sponges. They are characterized by spicules made out of calcium carbonate in the form of calcite or aragonite. While the spicules in most species have three points, in some species they have either two or four points.
Demosponges are the most diverse class in the phylum Porifera. They include 76.2% of all species of sponges with nearly 8,800 species worldwide. They are sponges with a soft body that covers a hard, often massive skeleton made of calcium carbonate, either aragonite or calcite. They are predominantly leuconoid in structure. Their "skeletons" are made of spicules consisting of fibers of the protein spongin, the mineral silica, or both. Where spicules of silica are present, they have a different shape from those in the otherwise similar glass sponges.
The Treatise on Invertebrate Paleontology published by the Geological Society of America and the University of Kansas Press, is a definitive multi-authored work of some 50 volumes, written by more than 300 paleontologists, and covering every phylum, class, order, family, and genus of fossil and extant invertebrate animals. The prehistoric invertebrates are described as to their taxonomy, morphology, paleoecology, stratigraphic and paleogeographic range. However, genera with no fossil record whatsoever have just a very brief listing.
The Calcinea are a subclass of the calcareous sponges. Its phylum is Porifera and class is Calcarea. Branching is usually dichotomous or umbellate with anastomoses, which gives rise to reticulate growths on stalks in adults. Most varieties are coral red or sulphur yellow.
Animals are multicellular eukaryotic organisms that form the biological kingdom Animalia. With few exceptions, animals consume organic material, breathe oxygen, are able to move, reproduce sexually, and grow from a hollow sphere of cells, the blastula, during embryonic development. Over 1.5 million living animal species have been described—of which around 1 million are insects—but it has been estimated there are over 7 million in total. Animals range in size from 8.5 millionths of a metre to 33.6 metres (110 ft) long and have complex interactions with each other and their environments, forming intricate food webs. The study of animals is called zoology.
The pinacoderm is the outermost layer of body cells (pinacocytes) of organisms of the phylum Porifera (sponges), equivalent to the epidermis in other animals.
The siliceous sponges form a major group of the phylum Porifera, consisting of classes Demospongiae and Hexactinellida. They are characterized by spicules made out of silicon dioxide, unlike calcareous sponges.
Pinacocytes are flat cells found on the outermost layer (Pinacoderm) of a sponge.
Chondrilla is a sea sponge genus belonging to the phylum Porifera.
Aaptos globosum is a sea sponge belonging to the phylum Porifera. The species was described in 1994.
Aaptos tentum is a sea sponge belonging to the phylum Porifera. The species was described in 1994.
Arthur Dendy was an English zoologist known for his work on marine sponges and the terrestrial invertebrates of Victoria, Australia, notably including the "living fossil" Peripatus. He was in turn professor of zoology in New Zealand, in South Africa and finally at King's College London. He was a Fellow of the Royal Society.
Turonia is an extinct genus of sea sponges belonging to the class Demospongiae.
Verongiida is an order of sea sponges within the phylum Porifera. The "skeleton" in these sponges is made up of spongin, rather than of spicules. They live in marine environments.
Verongimorpha is the name of a subclass of sea sponges within the phylum Porifera. It was first authenticated and described by Erpenbeck et al. in 2012.
Heteroscleromorpha is a subclass of demosponges within the phylum Porifera.
The Petalonamae are a proposed extinct group of animals, as sister of the Eumetazoa. Together with the Eumetazoa, they form a basal animal group, as sister of the Porifera.
