Rhabdopleurida


Rhabdopleurida is one of three orders in the class Pterobranchia, which are small, worm-shaped animals. Members belong to the hemichordates. 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.
Rhabdopleura is the best studied pterobranch in developmental biology. Some claim Rhabdopleura is an extant
graptolite.

Taxonomy

This small order is monotypic. It has only a single genus, containing four to six living species.
Order Rhabdopleurida Fowler 1892