Rhabdopleura

Rhabdopleura is a genus of colonial sessile hemichordates belonging to the Pterobranchia class. They are exclusively marine, benthic organisms whose species occur within all major oceans and range in habitat from intertidal to c. 900 m. 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 graptolites.

Rhabdopleura is the best studied pterobranch in developmental biology. Research in the 2010s by Jörg Maletz and other paleontologists and biologists have demonstrated that Rhabdopleura is an extant graptolite.