Rhabdopleurida is one of three orders in the class Pterobranchia, which are small, worm-shaped animals, and the only surviving graptolites. Members belong to the hemichordates.Animaldiversity.ummz.umich.edu Eol.org Species in this order are sessile, colonial, connected with a stolon, living in clear water and secrete tubes called tubarium. They have a single gonad, the gill slits are absent and the collar has two tentaculated arms.Modern Text Book of Zoology: Invertebrates Rhabdopleura is the best studied pterobranch in developmental biology.
Genera
The family contains a single extant genus, Rhabdopleura. Based on Maletz and Beli (2018), the following genera are recognised in the family Rhabdopleuridae:
Order Rhabdopleurida Fowler, 1892 Family Rhabdopleuridae Harmer, 1905 Genus Rhabdopleura Allman in Norman, 1869 Genus †Archaeolafoea Chapman, 1919 Genus †Chaunograptus Hall, 1882 Genus †Sokoloviina Kirjanov, 1968 Genus †Epigraptus Eisenack, 1941 Genus †Graptovermis Kozłowski, 1949 Genus †Haplograptus Ruedemann, 1933 Genus †Kystodendron Kozłowski, 1959 Genus †Rhabdopleurites Kozłowski, 1967 Genus †Rhabdopleuroides Kozłowski, 1961 Genus †Sphenoecium Chapman & Thomas, 1936 Genus †Stolonodendrum Kozłowski, 1949
Genera interpreted as possible stolons of members of Rhabdopleuridae:
Genus †Calyxhydra Kozłowski, 1959 Genus †Chitinodendron Eisenack, 1937 Genus †Diplohydra Kozłowski, 1959 Genus †Flexihydra Kozłowski, 1959 Genus †Lagenohydra Kozłowski, 1959 Genus †Palaeokylix Eisenack, 1932 Genus †Palaeotuba Eisenack, 1934 Genus †Phragmohydra Kozłowski, 1959 Genus †Rhabdohydra Kozłowski, 1959
References
Marinespecies.org ITIS.gov Hayward, P.J.; Ryland, J.S. (Ed.) (1990). The marine fauna of the British Isles and North-West Europe: 1. Introduction and protozoans to arthropods. Clarendon Press: Oxford, UK. . 627 pp.