Rhabdopleurida is one of three orders in the class
Pterobranchia, which are small, worm-shaped animals, are the only surviving
graptolites. Members belong to the
hemichordates.[2][3] 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.[4]Rhabdopleura is the best studied pterobranch in developmental biology.[5]Rhabdopleura is the only extant
graptolite.[6][7]
Taxonomy
This small order is
monotypic. It has only a single extant
genus, containing four to six living species.
^Sato, A; Rickards, RB; Holland PWH (2008). "The origins of graptolites and other pterobranchs: a journey from 'Polyzoa'". Lethaia. 41 (4): 303–316.
doi:
10.1111/j.1502-3931.2008.00123.x.
^Mitchell, Charles E.; Michael J. Melchin; Chris B. Cameron; Jörg Maletz (2012). "Phylogenetic analysis reveals that Rhabdopleura is an extant graptolite". Lethaia. 46: 34–56.
doi:
10.1111/j.1502-3931.2012.00319.x.
ISSN0024-1164.
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.
ISBN0-19-857356-1. 627 pp.