| Isastrea Temporal range: | |
|---|---|
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I. richardsoni showing calyces at various levels of magnification  | |
Scientific classification  | |
| Domain: | Eukaryota |
| Kingdom: | Animalia |
| Phylum: | Cnidaria |
| Class: | Hexacorallia |
| Order: | Scleractinia |
| Family: | † Montlivaltiidae |
| Genus: | † Isastrea Milne-Edwards & Haime, 1851 [4] |
Isastrea is an extinct genus of corals that lived during the Jurassic and Cretaceous periods. [3] Its fossils have been found in Europe, Africa, North America, [2] Asia and South America. [4]
Isastrea belonged to a group known as the hexacorals, so named for the shape of each individual polyp skeleton (corallite). [2] Each corallite was between 3 millimetres (0.12 in) and 15 millimetres (0.59 in) in diameter. In addition, 30–80 septa (walls dividing body cavities) were present in each animal. [3] Its walls were "weak, discontinuous or absent". In some species, adjacent septa would fuse. Dissepiments ("small blistery plates" serving the purpose of internal support) were plentiful in the animal. Columella (central "rod- or plate-like" structures) were present as well, but were not very strong. [1] The genus is believed to have lived in colonies (each of which could have been 39 inches (0.99 m) long) and formed coral reefs. [2] The colonies were "massive", [1] "encrusting, platey, dome-shaped or sometimes ramose". [3] It was a hermatypic coral, which require "warm, clear, shallow water" and live in symbiotic relationships with algae. [2] It is also likely that zooxanthellae (a kind of protozoa) lived on the coral. [3] It has been theorized that Isastrea could endure lower temperatures than most other hermatypic corals because it occurs farther north than them. [2]
At least 49 species of Isastrea have been described. [4] Milne-Edwards and Haime originally described the following species of Isastrea:
Scleractinia, also called stony corals or hard corals, are marine animals in the phylum Cnidaria that build themselves a hard skeleton. The individual animals are known as polyps and have a cylindrical body crowned by an oral disc in which a mouth is fringed with tentacles. Although some species are solitary, most are colonial. The founding polyp settles and starts to secrete calcium carbonate to protect its soft body. Solitary corals can be as much as 25 cm (10 in) across but in colonial species the polyps are usually only a few millimetres in diameter. These polyps reproduce asexually by budding, but remain attached to each other, forming a multi-polyp colony of clones with a common skeleton, which may be up to several metres in diameter or height according to species.
Brain coral is a common name given to various corals in the families Mussidae and Merulinidae, so called due to their generally spheroid shape and grooved surface which resembles a brain. Each head of coral is formed by a colony of genetically identical polyps which secrete a hard skeleton of calcium carbonate; this makes them important coral reef builders like other stony corals in the order Scleractinia. Brain corals are found in shallow warm water coral reefs in all the world's oceans. They are part of the phylum Cnidaria, in a class called Anthozoa or "flower animals". The lifespan of the largest brain corals is 900 years. Colonies can grow as large as 1.8 m (6 ft) or more in height.
Mussidae is a family of stony coral in the order Scleractinia. Following a taxonomic revision in 2012, the family is now restricted to species found in the Atlantic Ocean, with Pacific species transferred to the new family Lobophylliidae. Many species are referred to as brain coral because their generally spheroid form and grooved surface resembles the convolutions of a brain.
Oculina is a genus of colonial stony coral in the family Oculinidae. These corals are mostly found in the Caribbean Sea, the Gulf of Mexico and Bermuda but some species occur in the eastern Pacific Ocean. They occur at depths down to 1000 metres.
Acanthastrea is a genus of large polyp stony corals in the family Lobophylliidae. The colonies are massive and usually flat. The corallites are either circular or angular in shape. The septa are thick near the wall of the corallite, becoming thin near the columella, and have tall teeth. The polyps are extended only at night.
Gymnophyllum wardi, commonly known as button coral, is an extinct coral from the Pennsylvanian part of the Carboniferous period. The fossils are found in relatively few places worldwide; most specimens are known from the upper part of the Wewoka formation in and around Lake Okmulgee in Okmulgee State Park or the adjoining Dripping Springs State Park in Okmulgee County, Oklahoma in the United States.
Cycloseris is a genus of solitary disc corals in the family Fungiidae. They are found in the Indo-Pacific. They inhabit the lower reef slopes, and the areas between reefs with soft sediments. They tolerate turbid waters.
Oculinidae is a family of colonial corals.
The Agariciidae are a family of reef-building stony corals. This family includes cactus corals, plate corals, and lettuce corals. Members of the family include symbiotic algae called zooxanthellae in their tissues which help provide their energy requirements.
Siderastreidae is a family of reef building stony corals. Members of the family include symbiotic algae called Zooxanthellae in their tissues which help provide their energy requirements.
Dichocoenia is a monotypic genus of stony coral in the family Meandrinidae. It is represented by a single species, Dichocoenia stokesii, which is commonly known as pineapple coral, elliptical star coral, or pancake star coral. It is mostly found in the Caribbean Sea and the western Atlantic Ocean. Dichocoenia stokesii has irregular calyces and its form can be either a massive, hemispherical hump or a flat, platform-like structure.
Jules Haime was a French geologist, paleontologist and zoologist known for his research of coral.
Rhizangiidae is a family of stony corals in the order Scleractinia. This family is closely related to Oculinidae. Members of this family are non-reef building corals and reproduce from stolons. The corallites are small and the septa are simple.
Favites is a genus of stony corals in the family Merulinidae. Members of this genus are native to the Indo-Pacific region and their ranges extend from the Red Sea through the Indian Ocean and Western Pacific Ocean as far as Japan, the Line Islands and the Tuamotu Islands.
Leptoria is a genus of stony corals in the family Merulinidae. Members of this genus are known as brain corals or closed brain corals. They are native to the Indo-Pacific region and their ranges extend from the Red Sea through the Indian Ocean as far as Japan and the South Central Pacific Ocean.
Acropora elegans is a species of acroporid coral that was first described by Henri Milne-Edwards in 1860. Found in sheltered, sloping reefs, this species occurs at 30 to 60 m depth. The species is listed as vulnerable on the IUCN Red List, and has a decreasing population. It is not common and has a small range, and is listed under CITES Appendix II. It is more resistant to disease than other Acropora species.
Acropora pharaonis is a species of acroporid coral that was first described by Milne-Edwards and Haime in 1860. Found in marine, tropical, reefs on slopes sheltered from wave action, it occurs at depths of between 5 and 25 m. It is classed as a vulnerable species on the IUCN Red List, and it has a decreasing population. It is common and found over a large area and is classified under CITES Appendix II.
Isophyllia is a genus of stony coral in the subfamily Mussinae of the family Mussidae.
Scolymia cubensis is a solitary coral that belongs the genus Scolymia. It is a smooth disk coral whose shape usually consists of a flat, concave form (patellate) or an inverted cone form. However, a cylindrical shape may occur. They have a maximum diameter of 10 cm and have a symbiotic bond with zooxanthellae. Despite this, S. cubensis do not create their own reefs. Their colors normally consist of light green, light beige or a deep rusty red.