{{Short description|Extinct genus of corals}} {{Automatic taxobox | fossil_range = {{fossil range|Jurassic|Cretaceous|ref={{#tag:ref|Sources variously indicate Jurassic,<ref name="firefly" /> Middle–Late Cretaceous,<ref name="dk" /> and Jurassic–Cretaceous.<ref name="hup" />|group=note}}}} | image = Isastrea richardsoni.jpg | image_caption = ''I. richardsoni'' showing calyces at various levels of magnification thumb|Fossil Isastrea sp from Middle Jurassic, Tabas, Iran | taxon = Isastrea | authority = Milne-Edwards & Haime, 1851<ref name="database">{{cite web | url=https://paleobiodb.org/classic/checkTaxonInfo?taxon_no=54179 | title=''Isastrea'' | work=The Paleobiology Database | access-date=March 8, 2012}}</ref> }}
'''''Isastrea''''' is an extinct genus of corals that lived during the Jurassic and Cretaceous periods.<ref name="hup">{{cite book | title=Fossil Invertebrates | publisher=Harvard University Press | author=Taylor, Paul D. | year=2005 | isbn=0674025741 | chapter-url=https://books.google.com/books?id=7kPwZ2LeSAoC&pg=PA31 | chapter=Living in Colonies | page=31 | edition=reprint, illustrated |author2=Lewis, David N. | chapter-format=Google eBook}}</ref> Its fossils have been found in Europe, Africa, North America,<ref name="dk" /> Asia and South America.<ref name="database"/>
== Description == ''Isastrea'' belonged to a group known as the hexacorals, so named for the shape of each individual polyp skeleton (corallite).<ref name="dk" /> Each corallite was between {{convert|3|mm|in}} and {{convert|15|mm|in}} in diameter. In addition, 30–80 septa (walls dividing body cavities) were present in each animal.<ref name="hup" /> 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.<ref name="firefly">{{cite book | editor-first=Joanna | editor-last=Potts | title=Firefly Guide to Fossils | publisher=Firefly Books | year=2003 | edition=first | location=Buffalo, New York | pages=[https://archive.org/details/guidetofossilsfi00fire/page/62 62–63, 71] | isbn=1552978125 | url-access=registration | url=https://archive.org/details/guidetofossilsfi00fire/page/62 }}</ref> The genus is believed to have lived in colonies (each of which could have been {{convert|39|in|m}} long) and formed coral reefs.<ref name="dk" /> The colonies were "massive",<ref name="firefly" /> "encrusting, platey, dome-shaped or sometimes ramose".<ref name="hup" /> It was a hermatypic coral, which require "warm, clear, shallow water" and live in symbiotic relationships with algae.<ref name="dk" /> It is also likely that zooxanthellae (a kind of protozoa) lived on the coral.<ref name="hup" /> It has been theorized that ''Isastrea'' could endure lower temperatures than most other hermatypic corals because it occurs farther north than them.<ref name="dk">{{cite book | title=Prehistoric Life: The Definitive Visual History of Life on Earth | publisher=Dorling Kindersley | last=Palmer | first=Douglas | year=2009 | edition=first American | location=New York | page=236 | isbn=9780756655730|display-authors=etal}}</ref> thumb|Fossil Isastrea coral from Middle Jurassic, Tabas, Iran
== Species and fossil sites == At least 49 species of ''Isastrea'' have been described.<ref name="database" /> Milne-Edwards and Haime originally described the following species of ''Isastrea'': {{columns-list|colwidth=30em| *''I. oblonga'' from the Portland stone{{sfn|Milne-Edwards & Haime|1850–1854|p=74}} *''I. explanata'' and ''I. greenoughi'' from the coral rag{{sfn|Milne-Edwards & Haime|1850–1854|pp=94, 96}} *''I. conybearii'', ''I. limitata'', ''I. explanulata'', and ''I. serialis'' from the Great Oolite{{sfn|Milne-Edwards & Haime|1850–1854|pp=113–16}} *''I. richardsoni'', ''I. tenuistriata'', and ''I. lonsdalii'' from the Inferior Oolite{{sfn|Milne-Edwards & Haime|1850–1854|pp=138–9}} }}
== References == === Notes === {{Reflist|group=note}}
=== Inline citations === {{Reflist|2}}
=== General references === {{refbegin}} * {{cite book|title=A Monograph of the British Fossil Corals|last1=Milne-Edwards|first1=H.|last2=Haime|first2=Jules|location=London|year=1850–1854|publisher=Palæontographical Society|url=https://books.google.com/books?id=8v3pjSkVcC8C|ref={{SfnRef|Milne-Edwards & Haime|1850–1854|format=Google eBook}}}} {{refend}}
{{Taxonbar|from=Q6079002}}
Category:Scleractinia genera 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