''Cephalodiscus'' is a genus of

hemichordate Hemichordata is a phylum which consists of triploblastic, enterocoelomate, and bilaterally symmetrical marine deuterostome animals, generally considered the sister group of the echinoderms. They appear in the Lower or Middle Cambrian and include ...

s in the

monotypic In biology, a monotypic taxon is a taxonomic group (taxon) that contains only one immediately subordinate taxon. A monotypic species is one that does not include subspecies or smaller, infraspecific taxa. In the case of genera, the term "unispec ...

family Cephalodiscidae of the order

Cephalodiscida Cephalodiscida is one of two orders in the class Pterobranchia, which are small, worm-shaped animals. Members belong to the hemichordates. Species in this order are sessile, living in clear water and secrete tubes on the ocean floor. Taxonomy Th ...

Description

Unlike ''

Rhabdopleura ''Rhabdopleura'' is a genus of colonial sessile hemichordates belonging to the Pterobranchia class. As one of the oldest living genera with a fossil record dating back to the Middle Cambrian, it is also considered to be the only living genus of ...

'', ''Cephalodiscus'' species do not form large colonies and are only pseudocolonial. ''Cephalodiscus'' zooids are also more mobile than their ''Rhabdopleura'' counterparts, and are able to move around within tubaria. ''Cephalodiscus'' zooids can be produced via asexual budding. There are a few pairs of tentacled arms, whereas ''Rhabdopleura'' has only one pair of arms.

Species

19 living species of ''Cephalodiscus'' have been described: * '' Cephalodiscus agglutinans'' Harmer & Ridewood, 1914 * '' Cephalodiscus atlanticus'' Bayer, 1962 * '' Cephalodiscus australiensis'' Johnston & Muirhead, 1951 * ''

Cephalodiscus calciformis ''Cephalodiscus calciformis'' is a sessile hemichordate belonging to the order Cephalodiscida. It is the only pterobranch species with funnel A funnel is a tube or pipe that is wide at the top and narrow at the bottom, used for guiding liqu ...

'' Emig, 1977 * '' Cephalodiscus densus'' Andersson 1907 'Cephalodiscus rarus'' Andersson, 1907; ''Cephalodiscus anderssoni'' Gravier 1912* ''

Cephalodiscus dodecalophus ''Cephalodiscus dodecalophus'' is a sessile hemichordate belonging to the order Cephalodiscida. It has erect tubaria ''Tubaria'' is a genus of fungi in the family Tubariaceae. The genus is widely distributed, especially in temperate regions ...

'' McIntosh 1882 * ''

Cephalodiscus evansi ''Cephalodiscus evansi'' is a sessile hemichordate Hemichordata is a phylum which consists of triploblastic, enterocoelomate, and bilaterally symmetrical marine deuterostome animals, generally considered the sister group of the echinoderms. T ...

'' Ridewood * '' Cephalodiscus fumosus'' John, 1932 * ''

Cephalodiscus gilchristi ''Cephalodiscus gilchristi'' is a Sessility (zoology), sessile hemichordate belonging to the order Cephalodiscida. It is found in South Africa in 1908. Parasites The parasitic copepod ''Zanclopus cephalodisci'' has been found in the intestines o ...

'' Ridewood, 1908 * ''

Cephalodiscus gracilis ''Cephalodiscus gracilis'' is a sessile hemichordate Hemichordata is a phylum which consists of triploblastic, enterocoelomate, and bilaterally symmetrical marine deuterostome animals, generally considered the sister group of the echinoderms. ...

'' Harmer 1905 * ''

Cephalodiscus graptolitoides ''Cephalodiscus graptolitoides'' is a sessile hemichordate belonging to the order Cephalodiscida. It has encrusting tubaria ''Tubaria'' is a genus of fungi in the family Tubariaceae. The genus is widely distributed, especially in temperate r ...

'' Dilly 1993 * ''

Cephalodiscus hodgsoni ''Cephalodiscus hodgsoni'' is a sessile hemichordate Hemichordata is a phylum which consists of triploblastic, enterocoelomate, and bilaterally symmetrical marine deuterostome animals, generally considered the sister group of the echinoderms. ...

'' Ridewood, 1907 'Cephalodiscus aequatus'' Andersson 1907; ''Cephalodiscus inaequatus'' Andersson 1907* ''

Cephalodiscus indicus ''Cephalodiscus indicus'' is a sessile hemichordate belonging to the order Cephalodiscida Cephalodiscida is one of two orders in the class Pterobranchia, which are small, worm-shaped animals. Members belong to the hemichordates. Species in thi ...

'' Schepotieff 1909 * ''

Cephalodiscus kempi ''Cephalodiscus kempi'' is a sessile hemichordate belonging to the order Cephalodiscida. References kempi Jerreley Zanian John Slijger (born June 18, 1986), known by his stage name Kempi, is a Dutch rapper of Curaçaoan descent. From 2006 ...

'' John, 1932 * ''

Cephalodiscus levinsoni ''Cephalodiscus levinsoni'' is a sessile hemichordate belonging to the order Cephalodiscida Cephalodiscida is one of two orders in the class Pterobranchia, which are small, worm-shaped animals. Members belong to the hemichordates. Species in t ...

'' Harmer 1905 * ''

Cephalodiscus nigrescens ''Cephalodiscus nigrescens'' is a sessile hemichordate belonging to the order Cephalodiscida. Parasites The parasitic protozoa Protozoa (singular: protozoan or protozoon; alternative plural: protozoans) are a group of single-celled eukary ...

'' Lankester 1905 * ''

Cephalodiscus planitectus ''Cephalodiscus planitectus'' is a sessile hemichordate belonging to the order Cephalodiscida. Distribution It is found at a depth of 100–300 metres off the island of Jōgashima, Sagami Bay, Japan. Anatomy There are three pairs of arms with ...

'' Miyamoto, Nishikawa and Namikawa, 2020 * ''

Cephalodiscus sibogae ''Cephalodiscus sibogae'' is a sessile hemichordate belonging to the order Cephalodiscida Cephalodiscida is one of two orders in the class Pterobranchia, which are small, worm-shaped animals. Members belong to the hemichordates. Species in thi ...

'' Harmer 1905 * ''

Cephalodiscus solidus ''Cephalodiscus solidus'' is a sessile hemichordate belonging to the order Cephalodiscida. References solidus Solidus (Latin for "solid") may refer to: * Solidus (coin), a Roman coin of nearly solid gold * Solidus (punctuation), or slash, ...

'' Andersson, 1907 ''

'' is the most recently discovered species. It was described in 2020 from specimens found in Sagami Bay off the southern coast of

Honshu , historically called , is the largest and most populous island of Japan. It is located south of Hokkaidō across the Tsugaru Strait, north of Shikoku across the Inland Sea, and northeast of Kyūshū across the Kanmon Straits. The island separ ...

, Japan. Extinct species include: * †''

Cephalodiscus lutetianus ''Cephalodiscus'' is a genus of hemichordates in the monotypic family Cephalodiscidae of the order Cephalodiscida. Description Unlike ''Rhabdopleura'', ''Cephalodiscus'' species do not form large colonies and are only pseudocolonial. ''Cephalod ...

'' Abrard, Dollfus & Soyer 1950 * †'' Cephalodiscus nusplingensis'' Schweigert & Dietl 2013

References

External links

* * Animal genera Pterobranchia {{hemichordate-stub