Cephalodiscida
{{Short description|Order in the class Pterobranchia in the phylum Hemichordata}}
{{Taxobox
| name = Cephalodiscida
| image = Cephalodiscus dodecalophus McIntosh.png
| image_caption = Cephalodiscus dodecalophus
| regnum = Animalia
| phylum = Hemichordata
| classis = Pterobranchia
| ordo = Cephalodiscida
| ordo_authority = Fowler, 1892
| subdivision_ranks = Families
| subdivision = * Cephalodiscidae
| synonyms =
- Atubaridae Sato 1936
- Eocephalodiscidae Kozlowski 1949
- Melanostrophidae Zessin & von Puttkamer 1994
}}
Cephalodiscida is one of two orders in the class Pterobranchia, which are small, worm-shaped animals. Members belong to the hemichordates.[http://animaldiversity.ummz.umich.edu/site/accounts/classification/Cephalodiscida.html animaldiversity.ummz.umich.edu] {{webarchive |url=https://web.archive.org/web/20110629051029/http://animaldiversity.ummz.umich.edu/site/accounts/classification/Cephalodiscida.html |date=June 29, 2011 }}[http://www.eol.org/pages/8855 Eol.org] Species in this order are sessile, living in clear water and secrete tubes on the ocean floor.Shipley, A.E. (1902). Zoology: An Elementary Textbook. Cambridge: Cambridge University Press.
Taxonomy
The order is a small one, with only two known families, each containing a single extant genus. The validity of the family Atubaridae, who has only a sole member, is regarded as questionable.{{Cite journal|last=Halanych|first=K. M.|date=1996-02-01|title=Convergence in the Feeding Apparatuses of Lophophorates and Pterobranch Hemichordates Revealed by 18S rDNA: An Interpretation|url=https://www.journals.uchicago.edu/doi/10.2307/1542669|journal=The Biological Bulletin|volume=190|issue=1|pages=1–5|doi=10.2307/1542669|issn=0006-3185|url-access=subscription}}
- Order Cephalodiscida Fowler 1892{{cite journal |last=Maletz |first=Jörg| title=The classification of the Pterobranchia (Cephalodiscida and Graptolithina) |journal=Bulletin of Geosciences |year=2014 |volume=89 |issue=3 |pages=477–540 |doi=10.3140/bull.geosci.1465 |issn=1214-1119|doi-access=free }}
- Family Cephalodiscidae Harmer 1905
- Genus †Aellograptus Obut 1964
- Genus †Eocephalodiscus Kozlowski 1938 ex Kozlowski 1949
- Genus †Melanostrophus Öpik 1930 ex Öpik 1933
- Genus †Pterobranchites Kozlowski 1967
- Genus Atubaria Sato 1936
- Genus Cephalodiscus M'Intosh 1882
- Family †Rotaciurcidae Briggs and Koch 2023
- Genus †Rotaciurca Briggs and Koch 2023
References
{{Wikispecies}}
{{Reflist}}
Harmer. S. F. 1905. The Pterobranchia ol the Siboga-Expedition. Siboga Exped. Monogr. 26. 1-131
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