Isastrea
Isastrea is an extinct genus of corals that lived during the Jurassic and Cretaceous periods. Its fossils have been found in Europe, Africa, North America, Asia and South America.
Description
Isastrea belonged to a group known as the hexacorals, so named for the shape of each individual polyp skeleton. Each corallite was between and in diameter. In addition, 30–80 septa were present in each animal. Its walls were "weak, discontinuous or absent". In some species, adjacent septa would fuse. Dissepiments were plentiful in the animal. Columella were present as well, but were not very strong. The genus is believed to have lived in colonies and formed coral reefs. The colonies were "massive", "encrusting, platey, dome-shaped or sometimes ramose". It was a hermatypic coral, which require "warm, clear, shallow water" and live in symbiotic relationships with algae. It is also likely that zooxanthellae lived on the coral. It has been theorized that Isastrea could endure lower temperatures than most other hermatypic corals because it occurs farther north than them.Species and fossil sites
At least 49 species of Isastrea have been described. Milne-Edwards and Haime originally described the following species of Isastrea:Inline citations
General references
Category:Prehistoric Hexacorallia genera
Category:Mesozoic invertebrates
Category:Jurassic animals of Europe
Category:Cretaceous animals of Africa
Category:Mesozoic animals of Asia
Category:Mesozoic animals of North America
Category:Mesozoic animals of South America
Category:Jurassic Argentina
Category:Jurassic Colombia
Category:Jurassic Peru
Category:Cretaceous Venezuela
Category:Fossil taxa described in 1851
Category:Taxa named by [Henri Milne-Edwards]
Category:Taxa named by Jules Haime