''Rhabdopleura'' is a

genus Genus ( plural genera ) is a taxonomic rank used in the biological classification of living and fossil organisms as well as viruses. In the hierarchy of biological classification, genus comes above species and below family. In binomial nom ...

of colonial

sessile Sessility, or sessile, may refer to: * Sessility (motility), organisms which are not able to move about * Sessility (botany), flowers or leaves that grow directly from the stem or peduncle of a plant * Sessility (medicine), tumors and polyps that ...

hemichordate Hemichordata is a phylum which consists of triploblastic, enterocoelomate, and bilaterally symmetrical marine deuterostome animals, generally considered the sister group of the echinoderms. They appear in the Lower or Middle Cambrian and includ ...

s belonging to the

Pterobranchia Pterobranchia is a class of small worm-shaped animals. They belong to the Hemichordata, and live in secreted tubes on the ocean floor. Pterobranchia feed by filtering plankton out of the water with the help of cilia attached to tentacles. The ...

class. As one of the oldest living genera with a fossil record dating back to the

Middle Cambrian Middle or The Middle may refer to: * Centre (geometry), the point equally distant from the outer limits. Places * Middle (sheading), a subdivision of the Isle of Man * Middle Bay (disambiguation) * Middle Brook (disambiguation) * Middle Creek ...

, it is also considered to be the only living

graptolite Graptolites are a group of colonial animals, members of the subclass Graptolithina within the class Pterobranchia. These filter-feeding organisms are known chiefly from fossils found from the Middle Cambrian ( Miaolingian, Wuliuan) through t ...

s. ''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

Species

List of species from Maletz (2014): ;Living species The genus ''Rhabdopleura'' contains at least five living species. * '' Rhabdopleura annulata'' Norman 1921 — Indo-Pacific region * '' Rhabdopleura compacta'' Hincks 1880 — Atlantic * '' Rhabdopleura normani'' Allmann, 1869 — Atlantic and parts of the Pacific * '' Rhabdopleura recondita'' Beli, Cameron and Piraino, 2018 — Mediterranean * '' Rhabdopleura striata'' Schepotieff 1909 — Pacific ( Sri Lanka) ;'' Nomen dubium'' (doubtful) * '' Rhabdopleura grimaldi'' Julien 1890 nomen dubium * ''

Rhabdopleura manubialis ''Rhabdopleura'' is a genus of colonial sessile hemichordates belonging to the Pterobranchia class. 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 ...

'' Jullien & Calvet 1903 nomen dubium ;Extinct species: * †''

Rhabdopleura delmari ''Rhabdopleura'' is a genus of colonial sessile hemichordates belonging to the Pterobranchia class. 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 ...

'' Mortelmans 1955 * †''

Rhabdopleura graysoni ''Rhabdopleura'' is a genus of colonial sessile hemichordates belonging to the Pterobranchia class. 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 ...

'' Chapman, Durman & Rickards 1995 * †''

Rhabdopleura hollandi ''Rhabdopleura'' is a genus of colonial sessile hemichordates belonging to the Pterobranchia class. 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 ...

'' Rickards, Chapman & Temple 1984 * †''

Rhabdopleura kozlowskii ''Rhabdopleura'' is a genus of colonial sessile hemichordates belonging to the Pterobranchia class. 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 ...

'' Kulicki 1969 * †'' Rhabdopleura obuti'' Durman & Sennikov 1993 * †''

Rhabdopleura sinica ''Rhabdopleura'' is a genus of colonial sessile hemichordates belonging to the Pterobranchia class. 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 ...

'' Chapman, Durman & Rickards 1995 * †''

Rhabdopleura vistulae ''Rhabdopleura'' is a genus of colonial sessile hemichordates belonging to the Pterobranchia class. 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 ...

'' Kozlowski 1956

Fossil record

The

fossil record A fossil (from Classical Latin , ) is any preserved remains, impression, or trace of any once-living thing from a past geological age. Examples include bones, shells, exoskeletons, stone imprints of animals or microbes, objects preserved ...

for ''Rhabdopleura'' dates back to the

. There are also ''Rhabdopleura'' fossils from the

Eocene The Eocene ( ) Epoch is a geological epoch that lasted from about 56 to 33.9 million years ago (mya). It is the second epoch of the Paleogene Period in the modern Cenozoic Era. The name ''Eocene'' comes from the Ancient Greek (''ēṓs'', " ...

.A.J. Chapman; P.N. Durman; R.B. Rickards. 1995
Rhabdopleuran hemichordates: new fossil forms and review
''Proceedings of the Geologists' Association'' Volume 106, Issue 4, 1995, Pages 293-303.

References

{{Taxonbar, from=Q2808627 Graptolites Hemichordate genera Extant Cambrian first appearances *