Cephalodiscus is a genus of hemichordates in the monotypic family Cephalodiscidae of the order Cephalodiscida.
Unlike Rhabdopleura, 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.[2]
19 living species of Cephalodiscus have been described:[3]
Cephalodiscus planitectus is the most recently discovered species. It was described in 2020 from specimens found in Sagami Bay off the southern coast of Honshu, Japan.[4]
Extinct species include:
The Cephalodisci are endemic to the Antarctic, whose relative inaccessibility has historically limited human study of the genus. Ridewood suggests that the Erebus and Terror may have unwittingly encountered C. Nigrescens specimens, but until the Swedish Antarctic Expedition of 1901-1903, only C. Dodecalphus had been identified, via dredged Magellanic-Straits material.[5]
Cephalodiscus is a genus of hemichordates in the monotypic family Cephalodiscidae of the order Cephalodiscida.
