''Asoriculus'' is an extinct

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 terrestrial

shrews Shrews (family Soricidae) are small mole-like mammals classified in the order Eulipotyphla. True shrews are not to be confused with treeshrews, otter shrews, elephant shrews, West Indies shrews, or marsupial shrews, which belong to different ...

in the subfamily

Soricinae The red-toothed shrews of the subfamily Soricinae are one of three living subfamilies of shrews, along with Crocidurinae (white-toothed shrews) and Myosoricinae (African white-toothed shrews). In addition, the family contains the extinct subfamil ...

(red-toothed shrews) and tribe

Nectogalini Nectogalini is a tribe of Old World water shrews within the family Soricidae. As of late 2007, it consisted of six extant genera and 25 species, with some of the latter being further divided into subspecies. Adaptation to semiaquatic life M ...

. The best known species, ''Asoriculus gibberodon'' was widespread in Europe from the Late

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 ...

to the Early Pleistocene. Insular species are known from the

Mediterranean The Mediterranean Sea is a sea connected to the Atlantic Ocean, surrounded by the Mediterranean Basin and almost completely enclosed by land: on the north by Western Europe, Western and Southern Europe and Anatolia, on the south by North Africa ...

islands of

Sicily (man) it, Siciliana (woman) , population_note = , population_blank1_title = , population_blank1 = , demographics_type1 = Ethnicity , demographics1_footnotes = , demographi ...

(''A. burgioi'' Late

Pliocene The Pliocene ( ; also Pleiocene) is the epoch in the geologic time scale that extends from 5.333 million to 2.58Corsica-

Sardinia Sardinia ( ; it, Sardegna, label=Italian, Corsican and Tabarchino ; sc, Sardigna , sdc, Sardhigna; french: Sardaigne; sdn, Saldigna; ca, Sardenya, label=Algherese and Catalan) is the second-largest island in the Mediterranean Sea, after ...

including ''A. corsicanus'' (Late Pliocene-Early Pleistocene) and ''A. similis'' (Early Pleistocene- Late Pleistocene/

Holocene The Holocene ( ) is the current geological epoch. It began approximately 11,650 cal years Before Present (), after the Last Glacial Period, which concluded with the Holocene glacial retreat. The Holocene and the preceding Pleistocene togeth ...

). ''A. similis'' likely survived into the Holocene, when it became extinct after human settlement of the islands. The genus ''Nesiotites'' (Late Miocene/Early Pliocene-Holocene) from the Balearic Islands, including the

chronospecies A chronospecies is a species derived from a sequential development pattern that involves continual and uniform changes from an extinct ancestral form on an evolutionary scale. The sequence of alterations eventually produces a population that is p ...

''N. rafelinensis'' (earliest Pliocene), ''N. ponsi'' (Late Pliocene) and ''N. hidalgo'' (Middle Pleistocene-Holocene) is considered to descend from ''Asoriculus,'' likely ''A. gibberodon.'' The insular species of ''Asoriculus'' from Sicily and Corsica-Sardinia were formerly included in ''Nesiotites'', but ''Nesiotites'' was later circumscribed to only include the Balearic species, as otherwise the genus would likely be

polyphyletic A polyphyletic group is an assemblage of organisms or other evolving elements that is of mixed evolutionary origin. The term is often applied to groups that share similar features known as homoplasies, which are explained as a result of conver ...

. The last ''Nesiotites'' chronospecies, ''N. hidalgo'', became extinct shortly after human settlement of the Balearics around 2500 BC. Both the insular species of ''Asoriculus'' and ''Nesiotites'' are larger than ''A. gibberodon,'' which has been suggested to be the result of

island gigantism Island gigantism, or insular gigantism, is a biological phenomenon in which the size of an animal species isolated on an island increases dramatically in comparison to its mainland relatives. Island gigantism is one aspect of the more general Fos ...

, with the ''Nesiotites'' lineage experiencing a gradual increase in size over time. Based on DNA from ''Nesotites'', and morphological similarities ''Asoriculus'' is considered to be most closely related to the

Himalayan shrew The Himalayan shrew (''Soriculus nigrescens'') is found in Bhutan, China, India, Myanmar, and Nepal, is currently the only species in the genus ''Soriculus'' within the tribe Nectogalini, although the species ''Chodsigoa'' and ''Episoriculus'', w ...

(''Soriculus''). A

molecular clock The molecular clock is a figurative term for a technique that uses the mutation rate of biomolecules to deduce the time in prehistory when two or more life forms diverged. The biomolecular data used for such calculations are usually nucleo ...

analysis suggests that Himalayan shrews and Balearic shrews diveraged approximately 6.44 million years ago.

References

Pliocene first appearances Holocene extinctions Mammal genera {{redtoothed-shrew-stub