Isorophida

{{Short description|Extinct order of marine invertebrates}} {{Automatic taxobox | fossil_range = {{fossil range|488.3|272.5}} | image = New form of Agelacrinites.png | image_caption = ''Lepidodiscus'', an agelacrinitid isorophid | taxon = Isorophida | authority = Bell 1974 | subdivision_ranks = Suborders and Families | subdivision_ref = | subdivision = * {{extinct}}Isorophina<ref name=sz2011>{{harvnb|Sumrall|Zamora|2011}}</ref><ref>{{harvnb|Sumrall|2009}}</ref> ** {{extinct}}Isorophidae ** {{extinct}}Agelacrinitidae * {{extinct}}Lebetodiscina<ref>{{harvnb|Sumrall|Phelps|2021}}</ref> ** {{extinct}}Lebetodiscidae ** {{extinct}}Carneyellidae * ''incertae sedis'' ** †Pyrgocystidae<ref name=sz2011 />}}

'''Isorophida''' is an extinct order of prehistoric echinoderms in the class Edrioasteroidea. Isorophids are characterized by a disc-shaped, dome-shaped or club-shaped theca with ambulacra typically limited to the upward-facing oral surface which is bordered by an peripheral rim that flares outward parallel to the substrate. The aboral (substrate-facing) surface is unplated.<ref name=Bell>{{harvnb|Bell|1974|pp=41}}</ref>

Isorophids are the most common order of edrioasteroids.<ref name=Bell />

== References == {{Reflist}}

=== Works cited === {{refbegin}} * {{cite journal|last1=Bell |first1=Bruce M. |year=1974 |title=A Study of North American Edrioasteroidea |journal=New York State Museum and Science Service Memoir |volume=21}} {{small|(Note that the front cover gives the year as 1976, however the inside cover gives the correct year of 1974 as corroborated by the publisher's listing at the [https://www.nysl.nysed.gov/scandocs/museummemoirs New York State Museum Memoirs] page)}} * {{cite journal|last1=Sumrall |first1=Colin D. |year=2009 |title=First Definite Record of Permian Edrioasteroids: ''Neoisorophusella maslennikovi'' n. sp. from the Kungurian of Northeast Russia |journal=Journal of Paleontology |volume=83 |number=6 |pages=990–993 |jstor=20627684}} * {{cite journal|last1=Sumrall |first1=Colin D. |last2=Phelps |first2=Daniel |year=2021 |title=''Spiracarneyella'', a new carneyellid edrioasteroid from the Upper Ordovician (Katian) of Kentucky and Ohio and comments on carneyellid heterochrony |journal=Journal of Paleontology |volume=95 |number=3 |pages=624–629 |doi=10.1017/jpa.2020.97}} * {{cite journal|last1=Sumrall |first1=Colin D. |last2=Zamora |first2=Samuel |year=2011 |title=Ordovician edrioasteroids from Morocco: faunal exchanges across the Rheic Ocean |journal=Journal of Systematic Palaeontology |volume=9 |number=3 |pages=425–454 |doi=10.1080/14772019.2010.499137}} {{refend}}

== External links ==

* [https://paleobiodb.org/classic/checkTaxonInfo?taxon_no=30744 Isorophida] at fossilworks

Category:Edrioasteroidea Category:Prehistoric animal orders Category:Echinoderm orders Category:Fossil taxa described in 1974