''Chthamalus'' (χθαμαλός, "flat" or "on the ground") is a

genus Genus ( plural genera ) is a taxonomic rank used in the biological classification of extant taxon, living and fossil organisms as well as Virus classification#ICTV classification, viruses. In the hierarchy of biological classification, genus com ...

barnacle A barnacle is a type of arthropod constituting the subclass Cirripedia in the subphylum Crustacea, and is hence related to crabs and lobsters. Barnacles are exclusively marine, and tend to live in shallow and tidal waters, typically in eros ...

s that is found along almost all non-boreal coasts of the

northern hemisphere The Northern Hemisphere is the half of Earth that is north of the Equator. For other planets in the Solar System, north is defined as being in the same celestial hemisphere relative to the invariable plane of the solar system as Earth's Nort ...

, as well as many regions in the southern hemisphere. These small barnacles have been studied in part because of the

taxonomic Taxonomy is the practice and science of categorization or classification. A taxonomy (or taxonomical classification) is a scheme of classification, especially a hierarchical classification, in which things are organized into groups or types. ...

confusion over a group of species that, by and large, are morphologically and ecologically quite similar. In recent years, molecular techniques have identified a number of

cryptic species In biology, a species complex is a group of closely related organisms that are so similar in appearance and other features that the boundaries between them are often unclear. The taxa in the complex may be able to hybridize readily with each oth ...

that have been subsequently confirmed by taxonomists using morphological measurements. Most recently the genus has been shown to be

paraphyletic In taxonomy (general), taxonomy, a group is paraphyletic if it consists of the group's most recent common ancestor, last common ancestor and most of its descendants, excluding a few Monophyly, monophyletic subgroups. The group is said to be pa ...

, with the genus ''Microeuraphia'' nested within ''Chthamalus''.

Field Identification

Identification of barnacles in the field can be challenging, and identification of particular species of ''Chthamalus'' is not considered reliable in the field other than a few species. However, a notable distinction in the arrangement of wall plates can help biologists distinguish Chthamalid barnacles from the other common barnacles in the family Balanidae. In chthamalid barnacles, the side plates overlap both the rostrum and the carina (the plates at the ends of the opercular opening), while in balanids one end plate (the rostrum) overlaps the adjoining side plates (rostrolaterals).

Species

The following species are included in the genus ''Chthamalus'': * '' Chthamalus angustitergum'' Pilsbry, 1916 * '' Chthamalus anisopoma'' Pilsbry, 1916 * ''

Chthamalus antennatus ''Chthamalus antennatus'', the six-plated barnacle is a species of intertidal barnacle found in eastern and southern Australia. Growing from two centimetres wide and one centimetre high. The barnacle is found on the coast, usually on rocks at or ...

'' Darwin, 1854 * '' Chthamalus barnesi'' Achituv & Safriel, 1980 * '' Chthamalus bisinuatus'' (Pilsbry, 1916) * '' Chthamalus challengeri'' Hoek, 1883 * '' Chthamalus dalli'' Pilsbry, 1916 (little brown barnacle) * '' Chthamalus dentatus'' Krauss, 1848 (tooth barnacle) * ''

Chthamalus fissus ''Chthamalus fissus'' is a species of star barnacle in the family Chthamalidae. References External links * Sessilia {{crustacean-stub Crustaceans described in 1854 ...

'' Darwin, 1854 * '' Chthamalus fragilis'' Darwin, 1854 (fragile barnacle) * '' Chthamalus hedgecocki'' Pitombo & Burton, 2007 * '' Chthamalus malayensis'' Pilsbry, 1916 * '' Chthamalus montagui'' Southward, 1976 (montagu's stellate barnacle) * '' Chthamalus moro'' Pilsbry, 1916 * '' Chthamalus newmani'' Chan, 2016 * '' Chthamalus panamensis'' Pilsbry, 1916 * ''

Chthamalus proteus ''Chthamalus'' (χθαμαλός, "flat" or "on the ground") is a genus of barnacles that is found along almost all non-boreal coasts of the northern hemisphere, as well as many regions in the southern hemisphere. These small barnacles have been ...

'' Dando & Southward, 1980 (Atlantic barnacle) * '' Chthamalus sinensis'' Ren, 1984 * ''

Chthamalus southwardi ''Chthamalus'' (χθαμαλός, "flat" or "on the ground") is a genus of barnacles that is found along almost all non-boreal coasts of the northern hemisphere, as well as many regions in the southern hemisphere. These small barnacles have been ...

'' Poltarukha, 2000 * '' Chthamalus southwardorum'' Pitombo & Burton, 2007 * ''

Chthamalus stellatus ''Chthamalus stellatus'', common name Poli's stellate barnacle, is a species of acorn barnacle common on rocky shores in South West England, Ireland, and Southern Europe. It is named after Giuseppe Saverio Poli. Description ''C. stellatus'' is ...

'' (Poli, 1791) (poli's stellate barnacle) * '' Chthamalus williamsi'' Chan & Cheang, 2015 * † '' Chthamalus graziani'' Carriol, 2008 * † '' Chthamalus ligusticus'' de Alessandri, 1895 * † '' Chthamalus nasus'' Carriol, 2008 * † '' Chthamalus robustus'' Carriol, 2008

References

Barnacles Taxa named by Camillo Ranzani Maxillopoda genera {{Maxillopoda-stub