Louisella

{{Short description|Extinct genus of worms}} {{Automatic taxobox | fossil_range = {{Fossil range|Middle Cambrian}} | image = Walcott Cambrian Geology and Paleontology II plate 18.jpg | image_caption = Retouched images from Walcott's description of ''Miskoia'', now synonymized with ''Louisella'' | taxon = Louisella | authority = Walcott, 1911 | subdivision = {{species list | L. pedunculata | Walcott, 1911}} }}

'''''Louisella''''' is a genus of worm known from the Middle Cambrian Burgess Shale. It was originally described by Charles Walcott in 1911 as a holothurian echinoderm,<ref>{{Cite journal| jstor = 1303225| pages = 750–755| title = Systematic Position of ''Eldonia ludwigi'' Walcott| journal = Journal of Paleontology| volume = 48| issue = 4| year = 1974 | last1 = Durham| first1 = J. W.}}</ref> and represents a senior synonym of ''Miskoia'', which was originally described as an annelid.<ref>{{Cite journal | url = https://en.wikisource.org/wiki/Page:Walcott_Cambrian_Geology_and_Paleontology_II.djvu/180 | author = Walcott, C. D.|year = 1911 |title=Cambrian Geology and Paleontology II. Middle Cambrian annelids|journal = Smithsonian Miscellaneous Collections | volume = 57 | issue = 5 | pages = 109–145|via=Wikisource}}</ref> 48 specimens of ''Louisella'' are known from the Greater Phyllopod bed, where they comprise < 0.1% 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> It has been stated to have palaeoscolecid-like sclerites,<ref>{{Cite journal | doi = 10.1111/j.1096-3642.1997.tb00136.x| title = The cuticular structure of the 495-Myr-old type species of the fossil worm ''Palaeoscolex, P. piscatorum'' (?Priapulida)| journal = Zoological Journal of the Linnean Society| volume = 119| pages = 69–82| year = 1997| last1 = Conway Morris | first1 = S.| doi-access = free}}</ref> though this is not in fact the case.<ref name="auto">Smith, M.R. 2015: A palaeoscolecid worm from the Burgess Shale. Palaeontology 58, 973–979. {{doi | 10.1111/pala.12210}}</ref>

It's also been interpreted as an annelid<ref>Madsen, F.J. 1957: On Walcott’s Supposed Cambrian Holothurians. Journal of Paleontology 31, 281–282.</ref> and a sipunculan,<ref>Howell, B.F. 1962: Worms. In Moore, R. C. (ed.), Treatise on Invertebrate Paleontology W (Miscellanea), W144–W177. Geological Society of America, New York.</ref> (neither on particularly compelling grounds) and a pripaulid,<ref>Conway Morris, S. 1977: Fossil priapulid worms. Special Papers in Palaeontology 20, 1–95.</ref> but it is more conservatively considered to represent an ecdysozoan worm;<ref name="auto"/> deep ecdysozoan relationships are not yet well resolved, making a more precise affiliation challenging.

== References == {{Reflist}}

== External links == * {{Cite web|date=2011|title=''Louisella pedunculata''|work=Burgess Shale Fossil Gallery|publisher=Virtual Museum of Canada|url=http://burgess-shale.rom.on.ca/en/fossil-gallery/view-species.php?id=75|archive-url=https://web.archive.org/20201112025257/http://burgess-shale.rom.on.ca/en/fossil-gallery/view-species.php?id=75|archive-date=2020-11-12|url-status=dead}}

Category:Burgess Shale fossils Category:Burgess Shale animals Category:Monotypic prehistoric protostome genera Category:Cambrian genus extinctions Category:Priapulida