Receptaculites

{{Short description|Extinct genus of algae}} {{Automatic taxobox | fossil_range = {{fossilrange|488|250}} | image = Receptaculitid.JPG | image_caption = Receptaculitid from the Ordovician of Estonia. | taxon = Receptaculites | authority = Defrance 1827 | subdivision_ranks = Species | subdivision_ref = <ref name="TPBDB">{{Cite web| url = https://paleobiodb.org/classic/checkTaxonInfo?taxon_no=56444 | publisher = The Paleobiology Database | access-date = 2011-08-15 | title = Family: Receptaculitidae | author = | year = }}</ref> | subdivision = *''R. arcticus'' Etheridge<ref name=AB_g46139/> *''R. biconstrictus'' E.O.Ulrich<ref name=AB_g46139/> *''R. maeandriformis'' A.N.Ivanov<ref name=AB_g46139/> *''R. monticulatus'' *''R. neptuni'' Defrance<ref name=AB_g46139/> *''R. occidentalis'' }}

'''''Receptaculites''''' is the name-bearing genus for an extinct group of conspicuous benthic marine genera, the '''receptaculitids''' (formally '''Receptaculitaceae''' or '''Receptaculitidae'''), that lived from the Early Ordovician through the Permian period, peaking in the Middle Ordovician. The group's phylogenetic origin has long been obscure, with some arguing that they were calcareous algae, probably of the order Dasycladales.<ref name=Byrnes>Byrnes, J.G. 1968. Notes on the nature and environmental significance of the Receptaculitaceae. Lethaia, vol. 1, p. 368-381.</ref> Receptaculitids lived in warm, shallow seas,<ref name=Byrnes /> but consensus disagreeing.<ref>{{Cite book|doi = 10.1007/978-3-642-52335-9_6| chapter=Cyclocrinitids | title=Calcareous Algae and Stromatolites | year=1991 | last1=Beadle | first1=S. C. | pages=114–124 | isbn=978-3-642-52337-3 }}</ref><ref>{{Cite book | doi = 10.7312/webb12678-032| chapter = 31. Receptaculitids and Algae| title = The Great Ordovician Biodiversification Event| year = 2004| last1 = Nitecki| first1 = Matthew H.| last2 = Webby| first2 = Barry D.| last3 = Spjeldnaes| first3 = Nils| last4 = Yong-Yi| first4 = Zhen| pages = 336–347| isbn = 9780231126786}}</ref> They have been described from all continents except Antarctica.<ref>Rietschel, S. and Nitecki, M.H. 1984. Ordovician Receptaculitid algae from Burma. Palaeontology, vol. 27, p. 415-420.</ref><ref name=AB_g46139>{{AlgaeBase genus|name=Receptaculites|id=46139|access-date=2022-02-28}}</ref> In some areas they were important reef-formers, and they also occur as isolated specimens.<ref>Pratt, B.R. and Weissenberger, J., 1988. Fore-slope Receptaculitid mounds from the Frasnian of the Rocky Mountains, Alberta. In: Reefs: Canada and adjacent areas, Canadian Society of Petroleum Geologists Memoir 13, p. 510-513.</ref>

[[File:KimmswickOzoraMidOrdReceptaculitid.jpg|thumb|left|Receptaculitid from the Kimmswick Limestone (Middle Ordovician) near Ozora, Missouri.]] [[File:Receptaculites oweni.jpg|left|thumb|''Receptaculites oweni'', late Ordovician, Red River Formation, Garson, Manitoba. ]] ''Receptaculites'' and its relatives have a double-spiral, radiating pattern of rhombus-shaped plates supported by spindle-like objects called meroms.<ref>{{cite web|url=https://woostergeologists.scotblogs.wooster.edu/2017/02/10/wooster%E2%80%99s-fossil-of-the-week-a-receptaculitid-middle-ordovician-of-missouri/|title=Wooster's Fossil of the Week: A receptaculitid (Middle Ordovician of Missouri)|first=Mark|last=Wilson|date=2017-02-10|accessdate=2021-05-19}}</ref> Fossils can usually be identified by the intersecting patterns of clockwise and counterclockwise rows of plates or stalk spaces, superficially similar to the arrangement of disk florets on a sunflower—hence the common name "sunflower coral" (''sic'').<ref>{{cite journal |last1=Stinchcomb |first1=Bruce L. |title=Missouri Fossils |journal=Rocks & Minerals |date=November 1997 |volume=72 |issue=6 |pages=393–399 |doi=10.1080/00357529709605072}}</ref>

Receptaculitids have sometimes been compared to the morphologically similar, but probably distantly related, cyclocrinitids.<ref>{{cite journal |last1=Nitecki |first1=Matthew H. |last2=Webby |first2=Barry D. |last3=Spjeldnaes |first3=Nils |last4=Yong-Yi |first4=Zhen |title=31. Receptaculitids and Algae |journal=The Great Ordovician Biodiversification Event |date=31 December 2004 |pages=336–347 |doi=10.7312/webb12678-032|isbn=9780231126786 }}</ref><ref>{{cite journal |last1=Beadle |first1=Steven C. |title=Dasyclads, cyclocrinitids and receptaculitids: comparative morphology and paleoecology |journal=Lethaia |date=January 1988 |volume=21 |issue=1 |pages=1–12 |doi=10.1111/j.1502-3931.1988.tb01745.x}}</ref>

Some dolomitic limestone deposits, such as Tyndall stone in Manitoba, Canada, are particularly rich in ''Receptaculites'' fossils.

==References== {{Reflist}} [[File:Tyndal Stone with fossil.jpg|thumb|left|Receptaculitid in Ordovician Tyndall limestone from Manitoba, Canada.]]

Category:Paleozoic plants Category:Ulvophyceae genera Category:Fossil algae Category:Early Ordovician first appearances Category:Permian genus extinctions Category:Paleozoic life of Ontario Category:Paleozoic life of Alberta Category:Paleozoic life of British Columbia Category:Paleozoic life of Manitoba Category:Paleozoic life of Newfoundland and Labrador Category:Paleozoic life of the Northwest Territories Category:Paleozoic life of Nunavut Category:Paleozoic life of Quebec