View source for Scenella

{{Short description|Genus of molluscs (fossil)}}
{{Taxobox
| fossil_range = {{fossil range|Cambrian Stage 3|Late Ordovician|ref=<ref name=Babcock1988/>}}
| image = Scenella tenuistriata.png
| image_caption = Dorsal view of the shell of ''Scenella tenuistriata''
| image2 = Scenella tenuistriata 2.png
| image2_caption = Lateral view of the shell of ''Scenella tenuistriata''
| regnum = [[Animalia]]
| phylum = [[Mollusca]]
| ordo =
| superfamilia = † [[Scenelloidea]]
| familia = † '''Scenellidae'''
| familia_authority = [[Samuel Almon Miller|S. A. Miller]], 1889<ref>[[Samuel Almon Miller|Miller S. A.]] (after October 1889). North American geology and palaeontology: 389.</ref>
| genus= '''''Scenella'''''
| genus_authority = [[Elkanah Billings|Billings]], 1872
| subdivision_ranks = Species
| synonyms_ref = <ref name="Bouchet">Bouchet P. & Rocroi J.-P. (Ed.); Frýda J., Hausdorf B., Ponder W., Valdés Á. & Warén A. 2005. [http://www.vliz.be/Vmdcdata/imis2/ref.php?refid=78278 Classification and nomenclator of gastropod families]. Malacologia: International Journal of Malacology, 47(1-2). ConchBooks: Hackenheim, Germany. {{ISBN|3-925919-72-4}}. ISSN 0076-2997. 397 pp.</ref>
| synonyms =
* [[Helcionellinae]] Wenz, 1938
* Hampilinae Kobayashi, 1958
* Securiconidae Missarzhevsky, 1989
}}

'''''Scenella''''' is an [[extinct]] [[genus]] of [[fossil]] invertebrate animal which is generally considered to be a mollusc; at various times it has been suggested that this genus belongs with the [[gastropod]]s, the [[monoplacophora]]ns, or the [[helcionellid]]s, although no firm association with any of these classes has been established.<ref name=Yochelson1984>{{cite journal | year = 1984 | last1 = Yochelson | first1 = E. L. | last2 = Cid | first2 = D. G. L. | title = Reevaluation of the systematic position of Scenella | journal = Lethaia|volume =17 |issue =4 | pages = 331–340 | url = http://www3.interscience.wiley.com/journal/120036307/abstract | doi = 10.1111/j.1502-3931.1984.tb00679.x| doi-broken-date = 3 April 2025 | url-access = subscription }}{{dead link|date=February 2019|bot=medic}}{{cbignore|bot=medic}}</ref>  An affinity with the [[hydrozoa]] (as a flotation device) has been considered,<ref name=Babcock1988/> although some authors oppose this hypothesis.<ref name=Landing1992>{{Cite journal| doi = 10.1017/s0022336000033837| journal = Journal of Paleontology| year = 1992| volume = 66| issue = 2| title = ''Scenella'' and "A Chondrophorine (Medusoid Hydrozoan) from the Basal Cambrian (Placentian) of Newfoundland"| author = Landing| author2 = Narbonne| jstor = 1305918| pages = 338| bibcode = 1992JPal...66..338L| s2cid = 132296800}}</ref>  A gastropod affinity is defended on the basis of six pairs of internal muscle scars,<ref>{{Cite journal| journal = Journal of Paleontology| year = 1954| volume = 28| issue = 1| title = Internal Shell Structures in the Middle Cambrian Gastropod Scenella and the Problematic Genus Stenothecoides| author = Rasetti| jstor = 1300208| pages = 59–66}}</ref> whilst the serially-repeated nature of these scars suggests to other authors a monoplacophoran affinity.<ref name=Babcock1988/>  However the specimens showing this scarring have not been convincingly shown to belong to the genus ''Scenella''.<ref name=Babcock1988/> A similarity to the Ediacaran ''[[Ovatoscutum]]'' has also been drawn.<ref name="cite doi|10.1007/BF02985970">{{cite journal|author         = Benjamin M. Waggoner|author2= Allen G. Collins|title          = A new chondrophorine (Cnidaria, Hydrozoa) from the Cadiz Formation (Middle Cambrian) of California|journal	  = Paläontologische Zeitschrift|issn           = 0031-0220|doi            = 10.1007/BF02985970|pages          = 7–17|issue          =  1–2 |date           = March 1995|volume         = 69|bibcode= 1995PalZ...69....7W|s2cid= 128662109}}</ref>

==Description==
The shell of ''Scenella'' is elongated along its anterior-posterior axis, and comprises concentric rings around a conical central peak.  Radial and concentric corrugations exist in some species.<ref name="cite doi|10.1007/BF02985970"/>  Some specimens are preserved as organic films, others appear to have been infilled with calcite.<ref name=Babcock1988/>  They are usually preserved point-upwards, with their long axes consistently oriented; this probably represents their most stable position under their depositional current.<ref name=Babcock1988/>  Soft parts have never been reported in association with ''Scenella'', suggesting that the preserved fragments separated quickly from the associated tissue prior to burial.<ref name=Babcock1988/>

== Fossil occurrence ==

''Scenella'' lived from the [[Cambrian]] to the [[Ordovician]]. Its remains have been found in [[Antarctica]], [[Asia]], [[Europe]], and [[North America]].  Individual fossils are common throughout the [[Burgess shale]], where they often occur in dense aggregations.<ref name=Babcock1988>{{cite journal
 | last1=Babcock |first1=L. E.
 | last2=Robison |first2=R. A.
 | year = 1988
 | title = Taxonomy and paleobiology of some Middle Cambrian'' Scenella'' (Cnidaria) and Hyolithids (Mollusca) from western North America
 | url = http://kuscholarworks.ku.edu/dspace/bitstream/1808/3638/1/paleo.paper.121.pdf
 | volume = 121 | pages = 1–22
 | journal = University of Kansas Paleontological Contributions
 | hdl=1808/3638}}</ref>   Where they overlap, specimens deform as by draping.<ref name=Babcock1988/>  Specimens are sometimes cracked or torn, with margins often damaged by folding or "tattering".<ref name=Babcock1988/>  1206 specimens of ''Scenella'' are known from the Greater [[Phyllopod bed]], where they comprise 2.29% of the community.<ref name=Caron2006>{{cite journal|last1=Caron |first1=Jean-Bernard|last2=Jackson |first2=Donald A.|title=Taphonomy of the Greater Phyllopod Bed community, Burgess Shale|journal=PALAIOS |volume=21 |issue=5 |pages=451–65|date=October 2006|doi=10.2110/palo.2003.P05-070R|jstor=20173022|bibcode=2006Palai..21..451C |s2cid=53646959 }}</ref>

== Taxonomy ==
[[File:Scenella.jpg|thumb|''Scenella'' from the [[Burgess Shale]], Middle Cambrian, Walcott Quarry, near Field, British Columbia]]

''Scenella'' is the only genus in the family '''Scenellidae'''. This family has no subfamilies and ''Scenella'' is the [[type genus]] of the family Scenellidae.

The [[Taxonomy of the Gastropoda (Bouchet & Rocroi, 2005)|taxonomy of the Gastropoda by Bouchet & Rocroi, 2005]]<ref name="Bouchet"/> categorizes Scenellidae in the superfamilia [[Scenelloidea]] within the [[Taxonomy of the Gastropoda (Bouchet & Rocroi, 2005)#Paleozoic molluscs of uncertain systematic position|Paleozoic molluscs of uncertain systematic position]].

== Species ==
Species in the genus ''Scenella'' include:<ref>[https://paleobiodb.org/classic/checkTaxonInfo?taxon_no=7864 ''Scenella'']. [[Paleobiology Database]], accessed 16 August 2009.</ref>

{| class="wikitable sortable"
|-
! Species
! Authority
! Range
|-
| ''[[Scenella affinis]]''
| Ulrich and Schfield, 1897
|
|-
| ''[[Scenella amii]]''
| (Matthew, 1902) Babcock and Robinson 1988
| Burgess Shale (Mid Cambrian, {{Ma|Burgess Shale}})<ref name=Caron2006/>
|-
| ''[[Scenella anomala]]''
| (Billings, 1865) Wagner 2008
|-
| ''[[Scenella augusta]]''
| (Billings, 1865) Wagner 2008
|-
| ''[[Scenella barrandei]]''
| (Linnarsson, 1879) (Bergerg-Madsen and Peel, 1986)<ref>{{Cite journal
 | vauthors = BERGERG-MADSEN V, PEEL JS
 | year = 1986
 | title = ''Scenella barrandei'' (Mollusca) from the Middle Cambrian of Baltoscandia
 | journal = Norsk Geologisk Tidsskrift
 | pages = 81–86
 | volume = 66
 | issue = 1
 }}</ref>
|-
| ''[[Scenella beloitensis]]''
| Ulrich and Scofield (1897)
|-
| ''[[Scenella clotho]]''
| Walcott, 1936
|-
| ''[[Scenella compressa]]''
| Ulrich and Scofield (1897)
|-
| ''[[Scenella conica]]''
| Whiteaves, 1884
|-
| ''[[Scenella conula]]''
| (Walcott, 1884)
|-
| ''[[Scenella conicum]]''
| (Whitfield, 1886) Ulrich and Scofield (1897)
|-
| ''[[Scenella hujingtanensis]]''
| Yu, 1979
|-
| ''[[Scenella magnifica]]''
| Ulrich and Scofield (1897)
|-
| ''S.? mira ''
| Vasil’yeva, 1994
|-
| ''[[Scenella montrealensis]]''
| Billings (1865)
|-
| ''[[Scenella obtusa]]''
| (Sardeson, 1892) Ulrich and Scofield (1897)
|-
| ''[[Scenella orithyia]]''
| (Billings, 1865) Ulrich and Scofield (1897)
|-
| ''[[Scenella pretensa]]''
| Raymond, 1905
|-
| ''[[Scenella radialis]]''
| Ulrich and Scofield (1897)
|-
| ''[[Scenella radians]]''
| Babcock & Robinson
|-
| ''[[Scenella radiata]]''
| Yu, 1979
|-
| ''[[Scenella reticulata]]''
| (Billings, 1872) (type)<ref>{{cite journal|journal = Nat. Can.|series=2nd series|volume=vi|title=On some fossils from the primordial rocks of Newfoundland|pages=465–479|year=1872|last=Billings}}</ref>
|-
| ''[[Scenella retusa]]''
| (Ford, 1873)<ref>{{cite journal|journal=American Journal of Science|year=1873|author=Ford|title=On some new species of fossils from the Primordial or Potsdam group of Rensselaer County, New York (lower Potsdam)|series=3|volume=5|issue=27|pages=211–215|doi=10.2475/ajs.s3-5.27.211|bibcode=1873AmJS....5..211F|s2cid=130771815 |url=https://zenodo.org/record/1450106}}</ref>
|-
| ''[[Scenella unicarinata]]''
| (Kobayashi, 1934) Wagner 2008
|-
| ''[[Scenella varians]]''
| Walcott 1908
|-
| ''[[Scenella venillia]]''
| (Billings, 1865) Wagner 2008
|-
| ''[[Scenella tenuistriata]]''
|  [[Frederick Chapman (palaeontologist)|Chapman]], 1911
| Mid Cambrian<ref>[[Frederick Chapman (palaeontologist)|Chapman F.]] (1911). "New or Little Known Victorian Fossils in the National Museum". ''Proceedings of the Royal Society of Victoria'', Melbourne [https://archive.org/details/proceedingsofroy23roya '''23''']: [https://archive.org/stream/proceedingsofroy23roya#page/n427/mode/2up 305]-324. plate 58-61.; ''Scenella tenuistriata'' at [https://archive.org/stream/proceedingsofroy23roya#page/312/mode/2up 313]-314, [https://archive.org/stream/proceedingsofroy23roya#page/n450/mode/1up plate LIX.] figure 18 a,b.</ref>
|}

== References ==
{{Reflist}}

== External links ==
{{Commons category|Scenella}}
* {{Cite web|date=2011|title=''Scenella amii''|work=Burgess Shale Fossil Gallery|publisher=Virtual Museum of Canada|url=http://burgess-shale.rom.on.ca/en/fossil-gallery/view-species.php?id=111|archive-url=https://web.archive.org/20201112025257/http://burgess-shale.rom.on.ca/en/fossil-gallery/view-species.php?id=111|archive-date=2020-11-12|url-status=dead}}
*[http://www.fieldmuseum.org/evolvingplanet/popUps/CO20.html ''Scenella''] at the [[Field Museum]]'s Evolving Planet

{{Taxonbar|from=Q3951822}}

[[Category:Burgess Shale fossils]]
[[Category:Scenellidae]]
[[Category:Prehistoric mollusc genera]]
[[Category:Cambrian invertebrates]]
[[Category:Ordovician invertebrates]]
[[Category:Extinct animals of Antarctica]]
[[Category:Paleozoic animals of Asia]]
[[Category:Prehistoric animals of Europe]]
[[Category:Paleozoic animals of North America]]
[[Category:Cambrian Series 2 first appearances]]
[[Category:Late Ordovician extinctions]]
[[Category:Paleozoic life of Ontario]]
[[Category:Paleozoic life of Newfoundland and Labrador]]
[[Category:Paleozoic life of Quebec]]
[[Category:Taxa named by Elkanah Billings]]