Strophomenata

{{Short description|Extinct class of marine lamp shells}} {{Automatic taxobox | image = StrophomenidCornulitidOrdovician.jpg | image_caption = Strophomenid brachiopod with encrusting cornulitid worm tube (Upper Ordovician, SE Indiana). | fossil_range = {{Fossil range|516|205|Cambrian Stage 4-Triassic,<br />516-205 Ma<ref>[https://paleobiodb.org/classic/checkTaxonInfo?taxon_no=65923&is_real_user=1 Paleobiology Database]</ref>}} | taxon = Strophomenata | authority = Williams 1996 | subdivision_ranks = Orders | subdivision = * †Billingsellida * †Orthotetida * †Productida * †Strophomenida }}

'''Strophomenata''' is an extinct class of brachiopods in the subphylum Rhynchonelliformea.

They originated in the Cambrian period, hugely diversified during the Ordovician, and faced near extinction from the Permian-Triassic extinction. Only a few lingered around in the Triassic until eventually going extinct.<ref name=":0">{{Cite journal |last1=Carlson |first1=Sandra J. |last2=Leighton |first2=Lindsey R. |date=2001 |title=The Phylogeny and Classification of Rhynchonelliformea |url=https://www.cambridge.org/core/product/identifier/S1089332600000887/type/journal_article |journal=The Paleontological Society Papers |language=en |volume=7 |pages=27–52 |doi=10.1017/S1089332600000887 |issn=1089-3326|url-access=subscription }}</ref> They were an exceptionally diverse group of brachiopods, and within the group the Strophomenids of the early Paleozoic and Productids of the late Paleozoic hugely contributed to the immense diversity.

== Common features == In ''The phylogeny and classification of Rhynchonelliformea'', Strophomenates are described as having "no definite synapomorphies". A number of common features appear throughout the group, but there are many exceptions and none are universal to the group.

The common features of the Strophomenates include: #concavo-convex(sometimes convexi-concave), or plano-convex shells; #a laminar secondary shell layer with well developed pseudopunctae (microstructural features); #a bilobed cardinal process; #the existence of the pseudodeltidium; #a supra-apical/apical foramen, at least during juvenile stages, which is a feature associated to the egression of the pedicle during growth(many Strophomenates lose their pedicles after certain age).<ref name=":0" />

== Orders== ===Billingsellida=== {{Main|Billingsellida}} An order that contains the suborder Clitambonitidina (and others?) .

===Orthotetida=== {{Main|Orthotetida}} An order or superfamily that includes the Chilidiopsoidea.<ref name=Holmer2017>LE Holmer, Z Zhang, TP Topper, and L Popov 2017. The attachment strategies of Cambrian kutorginate brachiopods: the curious case of two pedicle openings and their phylogenetic significance. Journal of Paleontology, 2017.</ref> Ontogeny given by Bassett and Popov (2017), resembling that of Kutorginides.<ref name="Holmer2017"/>

Believed to be sister to Strophomenides, = Strophomenida + Billinsellida + Productida.<ref>Bassett, M.G., and Popov, L.E. (2017). Earliest ontogeny of the Silurian orthotetide brachiopod ~Coolinia~ and its significance for interpreting strophomenate phylogeny. Lethaia 50, 504–510.</ref>

Includes the Chileids (e.g. ''Coolinia'').

=== Strophomenida === {{Main|Strophomenida}} Originating in the Early Ordovician and persisting until the Carboniferous, the Strophomenids were an extremely diverse order. Strophomenids are usually divided into two groups - the Plectambonitoidea and the Strophomenoidea.<ref>{{Cite journal |last1=Congreve |first1=Curtis R. |last2=Krug |first2=Andrew Z. |last3=Patzkowsky |first3=Mark E. |date=2015 |editor-last=Sevastopulo |editor-first=George |title=Phylogenetic revision of the Strophomenida, a diverse and ecologically important Palaeozoic brachiopod order |journal=Palaeontology |language=en |volume=58 |issue=4 |pages=743–758 |doi=10.1111/pala.12177|doi-access=free |bibcode=2015Palgy..58..743C }}</ref> Some members used their short meaty pedicles for attachment, while many others lost their pedicle during growth and developed a free-lying lifestyle.<ref>{{Cite journal |last=Hoel |first=Ole A. |date=2014-01-21 |title=Palaeobiology of Silurian Leptaeninae (Brachiopoda) from Gotland, Sweden |journal=Paleontology Journal |language=en |volume=2014 |pages=1–14 |doi=10.1155/2014/716053 |issn=2314-4289|doi-access=free }}</ref> As such a lot of their shells are concavo-convex. Microstructural features of the Strophomenid shell include a cross-laminar structure, and a pseudopunctate laminar layer often found with taleolae.<ref name=":0" /> Well-known Strophomenids include ''Leptaena'', ''Sowerbyella'', ''Rafinesquina'', and ''Strophomena''.

== References == {{Reflist}}

== External links == * {{Wikispecies-inline}} * {{Commons-inline}} * {{fossilworks|id=65923 |title=Strophomenata |date= }}

Category:Strophomenata Category:Prehistoric protostome classes Category:Triassic extinctions