''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 hemichordates belonging to the Pterobranchia 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 Developmental biology is the study of the process by which animals and plants grow and develop. Developmental biology also encompasses the biology of regeneration, asexual reproduction, metamorphosis, and the growth and differentiation of st ...

. 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 Sri Lanka (, ; si, ශ්‍රී ලංකා, Śrī Laṅkā, translit-std=ISO (); ta, இலங்கை, Ilaṅkai, translit-std=ISO ()), formerly known as Ceylon and officially the Democratic Socialist Republic of Sri Lanka, is an ...

) ;''

Nomen dubium In binomial nomenclature, a ''nomen dubium'' (Latin for "doubtful name", plural ''nomina dubia'') is a scientific name that is of unknown or doubtful application. Zoology In case of a ''nomen dubium'' it may be impossible to determine whether a s ...

'' (doubtful) * ''

Rhabdopleura grimaldi ''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 ...

'' 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 ...

'' 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 ...

'' 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 ...

'' 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 ...

'' 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 ...

'' Kulicki 1969 * †''

Rhabdopleura obuti ''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 ...

'' 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 ...

'' 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 ...

'' 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 *