''Hemiarthrum setulosum'' is a

species A species () is often defined as the largest group of organisms in which any two individuals of the appropriate sexes or mating types can produce fertile offspring, typically by sexual reproduction. It is the basic unit of Taxonomy (biology), ...

chiton Chitons () are marine molluscs of varying size in the class Polyplacophora ( ), formerly known as Amphineura. About 940 extant and 430 fossil species are recognized. They are also sometimes known as sea cradles or coat-of-mail shells or suck ...

in the

family Family (from ) is a Social group, group of people related either by consanguinity (by recognized birth) or Affinity (law), affinity (by marriage or other relationship). It forms the basis for social order. Ideally, families offer predictabili ...

Hemiarthrumidae, and the only member of the

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 ...

''Hemiarthrum''. It was previously assigned to the family

Hanleyidae ''Hanleya'' is a genus of polyplacophoran molluscs known from Oligocene and 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 geologis ...

. ''Hemiarthrum setulosum'' represent one of the five major clades of chitons that are living. ''Hemiarthrim setulosum'' has an incomplete lateral tract in the nerve ring. They are the only known species to have an incomplete one. Sumner‐Rooney, Lauren, and Julia D. Sigwart. "Do chitons have a brain? New evidence for diversity and complexity in the polyplacophoran central nervous system." Journal of morphology 279.7 (2018): 936-949. ;Synonym * ''Hemiarthrum hamiltonorum'' Iredale & Hull, 1932: synonym of ''Hemiarthrum setulosum'' P. P. Carpenter n Dall 1876 (junior subjective synonym)

Distribution

This species occurs off the

Kerguelen Islands The Kerguelen Islands ( or ; in French commonly ' but officially ', ), also known as the Desolation Islands (' in French), are a group of islands in the subantarctic, sub-Antarctic region. They are among the Extremes on Earth#Remoteness, most i ...

and

Cape Horn Cape Horn (, ) is the southernmost headland of the Tierra del Fuego archipelago of southern Chile, and is located on the small Hornos Island. Although not the most southerly point of South America (which is Águila Islet), Cape Horn marks the nor ...

References

* Rochebrune, A.-T., 1889 - Polyplacophores. In Rochebrune, A.T. & Mabille, J., Mission Scientifique du Cap Horn, vol. 6, part. Zoologie, p. 131-143, pl9 * Spencer, H.G., Marshall, B.A. & Willan, R.C. (2009). Checklist of New Zealand living Mollusca. Pp 196-219. in: Gordon, D.P. (ed.) New Zealand inventory of biodiversity. Volume one. Kingdom Animalia: Radiata, Lophotrochozoa, Deuterostomia. Canterbury University Press, Christchurch

External links

Dall, W. H. (1876). Mollusks. In: J.H. Kidder, Contributions to the natural history of Kerguelen Island, made in connection with the United States "Transit-of-Venus" Expedition, 1874-1875, II. Bulletin of the United States National Museum. 3: pp. 42–48
Chitonida Monotypic chiton genera {{Chiton-stub