''Neotrigonia'' is a

genus Genus (; : genera ) is a taxonomic rank above species and below family (taxonomy), family as used in the biological classification of extant taxon, living and fossil organisms as well as Virus classification#ICTV classification, viruses. In bino ...

of living

saltwater Saline water (more commonly known as salt water) is water that contains a high concentration of dissolved salts (mainly sodium chloride). On the United States Geological Survey (USGS) salinity scale, saline water is saltier than brackish wat ...

clams Clam is a common name for several kinds of bivalve mollusc. The word is often applied only to those that are deemed edible and live as infauna, spending most of their lives halfway buried in the sand of the sea floor or riverbeds. Clams h ...

, in the family

Trigoniidae Trigoniidae is a taxonomic family of saltwater clams, marine bivalve mollusks in the superfamily Trigonioidea. There is only one living genus, '' Neotrigonia'', but in the geological past this family was well represented, widespread and common. ...

, which otherwise consists only of fossil genera. For a long time the entire family was thought to be long extinct, but a living species that is now placed in this genus was discovered in 1802. At that time it was assigned to the fossil genus '' Trigonia''. Currently, according to the

World Register of Marine Species The World Register of Marine Species (WoRMS) is a taxonomic database that aims to provide an authoritative and comprehensive catalogue and list of names of marine organisms. Content The content of the registry is edited and maintained by scien ...

, 8 extant species in this genus are recognized.

Discovery of the genus

Until the beginning of the 19th century, no living species in this superfamily had ever been discovered, although numerous fossil species were known. The superfamily was well known as fossils from the Devonian to the

Cretaceous The Cretaceous ( ) is a geological period that lasted from about 143.1 to 66 mya (unit), million years ago (Mya). It is the third and final period of the Mesozoic Era (geology), Era, as well as the longest. At around 77.1 million years, it is the ...

Period. In 1802, however,

François Péron François Auguste Péron (22 August 1775 – 14 December 1810) was a French naturalist and explorer. Life Péron was born in Cérilly, Allier, in 1775, the son of a tailor (not a harness maker as is frequently asserted). Although intended fo ...

discovered a living species in waters off the coast of

Tasmania Tasmania (; palawa kani: ''Lutruwita'') is an island States and territories of Australia, state of Australia. It is located to the south of the Mainland Australia, Australian mainland, and is separated from it by the Bass Strait. The sta ...

. In 1804,

Lamarck Jean-Baptiste Pierre Antoine de Monet, chevalier de Lamarck (1 August 1744 – 18 December 1829), often known simply as Lamarck (; ), was a French naturalist, biologist, academic, and soldier. He was an early proponent of the idea that biolo ...

named that species ''Trigonia margaritacea'', and Cossmann renamed the genus ''Neotrigonia'' in 1912. Today, eight living species are known to exist, all of which are found off the coast of Australia and Tasmania. ''Neotrigonia'' probably evolved from ''Eotrigonia'' (

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

Miocene The Miocene ( ) is the first epoch (geology), geological epoch of the Neogene Period and extends from about (Ma). The Miocene was named by Scottish geologist Charles Lyell; the name comes from the Greek words (', "less") and (', "new") and mea ...

) during the Miocene epoch.Francis, A.O. 2000. The Palaeobiology of the European Jurassic Trigoniidae. Ph.D. thesis, University of Birmingham, 323pp.

Species

Species within the genus ''Neotrigonia'' include: * '' Neotrigonia bednalli'' (Verco, 1907) * '' Neotrigonia gemma'' Iredale, 1924 * '' Neotrigonia jacksoni'' Morrison, 2011 * '' Neotrigonia kaiyomaruae'' Habe & Nomoto, 1976 * '' Neotrigonia lamarckii'' (Gray, 1838) * '' Neotrigonia margaritacea'' (Lamarck, 1804) * '' Neotrigonia strangei'' (A. Adams, 1854) * '' Neotrigonia uniophora'' (Gray in Jukes, 1847) Synonym * '' Neotrigonia horia'' Cotton, 195: synonym of '' Neotrigonia bednalli'' (Verco, 1907)

References

External links

PLOS paper which includes a photograph of a live individual of ''Neotrigonia lamarckii'', with the foot showing

Image showing internal soft parts of a ''Neotrigonia''

Rotterdam Museum image of a shell of ''Neotrigonia strangei''
Trigoniidae Bivalve genera {{bivalve-stub