| Keratosa | |
|---|---|
 | |
| Chelonaplysilla violacea off Réunion | |
Scientific classification  | |
| Kingdom: | Animalia |
| Phylum: | Porifera |
| Class: | Demospongiae |
| Subclass: | Keratosa Grant, 1861 [1] |
| Orders | |
| |
Keratosa, the keratose sponges or horny sponges, is a subclass of demosponges. [2]
Cnidaria is a phylum under kingdom Animalia containing over 11,000 species of aquatic animals found both in freshwater and marine environments, predominantly the latter.
Invertebrates are species of animal that neither possess nor develop a vertebral column, derived from the notochord. This includes all animals apart from the chordate subphylum Vertebrata. Familiar examples of invertebrates include arthropods, mollusks, annelid, and cnidarians.
The Neoproterozoic Era is the unit of geologic time from 1 billion to 538.8 million years ago.
Archaeocyatha is a taxon of extinct, sessile, reef-building marine sponges that lived in warm tropical and subtropical waters during the Cambrian Period. It is believed that the centre of the Archaeocyatha origin is 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.
Sponges, the members of the phylum Porifera, are a basal animal clade as a sister of the Diploblasts. They are multicellular organisms that have bodies full of pores and channels allowing water to circulate through them, consisting of jelly-like mesohyl sandwiched between two thin layers of cells.
Parazoa are a taxon with sub-kingdom category that is located at the base of the phylogenetic tree of the animal kingdom in opposition to the sub-kingdom Eumetazoa; groups together the most primitive forms, characterized by not having proper tissues or that, in any case, these tissues are only partially differentiated. They generally group a single phylum, Porifera, which lack muscles, nerves and internal organs, which in many cases resembles a cell colony rather than a multicellular organism itself. All other animals are eumetazoans, which do have differentiated tissues.
Eumetazoa, also known as Diploblasts, Epitheliozoa, or Histozoa, are a proposed basal animal clade as a sister group of the Porifera (Sponges). The basal Eumetazoan clades are the Ctenophora and the ParaHoxozoa. Placozoa is now also seen as an Eumetazoan in the ParaHoxozoa.
A seborrheic keratosis is a non-cancerous (benign) skin tumour that originates from cells in the outer layer of the skin. Like liver spots, seborrheic keratoses are seen more often as people age.
The Tonian is the first geologic period of the Neoproterozoic Era. It lasted from 1000 to 720 Mya. Instead of being based on stratigraphy, these dates are defined by the ICS based on radiometric chronometry. The Tonian is preceded by the Stenian Period of the Mesoproterozoic Era and followed by the Cryogenian.
Metacheiromys is an extinct genus of palaeanodont mammal from the paraphyletic subfamily Metacheiromyinae within paraphyletic family Metacheiromyidae, that lived in North America during the early to middle Eocene.
Dendroceratida is an order of sponges of the class Demospongiae. They are typically found in shallow coastal and tidal areas of most coasts around the world. They are generally characterized by concentric layers of fibers containing spongin, and by large flagellated chambers that open directly into the exhalant canals. Along with the Dictyoceratida, it is one of the two orders of demosponges that make up the keratose or "horny" sponges, in which a mineral skeleton is minimal or absent and a skeleton of organic spongin-containing fibers is present instead.
Although the phylogenetic classification of non-vertebrate animals remains a work-in-progress, the following taxonomy attempts to be useful by combining both traditional (old) and new (21st-century) paleozoological terminology.
The Chancelloriids are an extinct family of animal common in sediments from the Early Cambrian to the early Late Cambrian. Many of these fossils consists only of spines and other fragments, and it is not certain that they belong to the same type of organism. Other specimens appear to be more complete and to represent sessile, bag-like organisms with a soft skin armored with star-shaped calcareous sclerites from which radiate sharp spines.
Holozoa is a group of organisms that includes animals and their closest single-celled relatives, but excludes fungi. Holozoa is also an old name for the tunicate genus Distaplia.
The Filozoa are a monophyletic grouping within the Opisthokonta. They include animals and their nearest unicellular relatives.
Spicules are structural elements found in most sponges. Sponge spicules are made of calcium carbonate or silica. Large spicules visible to the naked eye are referred to as megascleres, while smaller, microscopic ones are termed microscleres. The meshing of many spicules serves as the sponge's skeleton and thus it provides structural support and potentially defense against predators. The composition, size, and shape of spicules are major characters in sponge systematics and taxonomy.
Dictyoceratida is an order of sponges in the subclass Ceractinomorpha containing five families. Along with the Dendroceratida, it is one of the two orders of demosponges that make up the keratose or "horny" sponges, in which a mineral skeleton is minimal or absent and a skeleton of organic fibers containing spongin, a collagen-like material, is present instead.
Dysidea arenaria is a species of marine sponge (poriferan) found in the Pacific Ocean. It is a member of the order Dictyoceratida, one of two sponge orders that make up the keratose or "horny" sponges in which a mineral skeleton is absent and a skeleton of organic fibers is present instead.
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.
Gert Wörheide is a German marine biologist who works mainly on marine invertebrates. He earned his doctorate in geobiology from Georg-August-Universität, following this with a post-doctorate at Queensland Museum (1998-2002), where he worked with John Hooper on sponges, a collaboration which continues.
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