Hydromyini is a very large, diverse tribe of muroid rodents in the subfamily Murinae. They are the dominant native rodents in Australasia and one of only two native rodent groups there, the other being the R. fuscipes group of the genus Rattus in the tribe Rattini.[1] They are also found in parts of Southeast Asia.

Hydromyini
Temporal range: Late Miocene to Recent
Giant white-tailed rat (Uromys caudimaculatus)
Scientific classification Edit this classification
Domain: Eukaryota
Kingdom: Animalia
Phylum: Chordata
Class: Mammalia
Order: Rodentia
Family: Muridae
Subfamily: Murinae
Tribe: Hydromyini
Gray, 1825
Genera

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Synonyms

Chiropodomyini Pagès et al. 2015

Taxonomy

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They are thought to be relatively early offshoots from the Murinae, with only Rattini and Phloeomyini being more basal than them. They likely colonized New Guinea (then a part of Sahul) from either the Sunda Shelf or the Philippines during the late Miocene or early Pliocene, about 5 million years ago, and diversified extremely rapidly. From here, they colonized Australia about 2-3 million years ago, undergoing major adaptive radiation.[2]

Earlier taxonomists formerly split this group into three subfamilies (Hydromyinae, Pseudomyinae, and an unnamed "Old Papuan group"). Although all were later merged into the Murinae, they were still retained as multiple tribes (Anisomyini, Hydromyini, Uromyini, and Conilurini), with other taxonomists splitting them even further. However, a 2008 study found them to comprise a single group that had undergone a rapid diversification after colonizing Sahul, and thus placed them all into a single tribe, Hydromyini.[2]

The genus Chiropodomys (formerly placed in a polyphyletic division containing Micromys, Hapalomys, and Vandeleuria) has been found to be the sister group to this tribe, but it has been debated over whether it belongs in its own tribe (Chiropodomyini) or is a basal member of the Hydromyini. The American Society of Mammalogists presently classifies it in Hydromyini.[3][4][5]

Although the name "Hydromyini" derives from the semiaquatic type genus Hydromys, which translates directly to "water mouse", only a few members of the tribe such as Hydromys and Xeromys are semiaquatic; the majority are terrestrial, and some such as Notomys are even specifically adapted to arid environments.

Distribution

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Their center of diversity is in New Guinea, with a secondary one in Australia, but they also range east to the Solomon Islands and west to Borneo and the Philippines, and, if the genus Chiropodomys is included, as far west as northeast India.[4] Members of this tribe in New Guinea and Australia are referred to as the "Old Endemic rodents", to differentiate them from the native Rattus species from the tribe Rattini, which colonized the regions much more recently.[2]

Species

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Species in the tribe include:[3][4][5]

Threats

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In Australia, many members of this tribe have gone extinct very rapidly since the 19th century due to introduced predators and habitat alteration (such as development and fire suppression). Prominent examples include the white-footed rabbit rat (Conilurus albipes), lesser stick-nest rat (Leporillus apicalis), blue-grey mouse (Pseudomys glaucus) and over half the recent species in the genus Notomys, most of which likely went extinct during the late 19th or early 20th centuries; many other species have also seen significantly reduced populations or range reductions. Genetic studies indicate that many of these species had relatively high genetic diversity prior to European colonization, indicating that they were not suffering from inbreeding beforehand and that high genetic diversity does not shield species from extinctions.[6] Another species, the Bramble Cay melomys (Melomys rubicola), which went extinct in the early 2010s, was the first recorded extinction of an animal due to sea level rise.[7]

References

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  1. ^ Prins, Herbert H. T.; Gordon, Iain J. (2014-01-23). Invasion Biology and Ecological Theory: Insights from a Continent in Transformation. Cambridge University Press. p. 198. ISBN 978-1-107-78297-6.
  2. ^ a b c Rowe, Kevin C.; Reno, Michael L.; Richmond, Daniel M.; Adkins, Ronald M.; Steppan, Scott J. (April 2008). "Pliocene colonization and adaptive radiations in Australia and New Guinea (Sahul): Multilocus systematics of the old endemic rodents (Muroidea: Murinae)". Molecular Phylogenetics and Evolution. 47 (1): 84–101. doi:10.1016/j.ympev.2008.01.001. ISSN 1055-7903. PMID 18313945.
  3. ^ a b Pagès, Marie; Fabre, Pierre-Henri; Chaval, Yannick; Mortelliti, Alessio; Nicolas, Violaine; Wells, Konstans; Michaux, Johan R.; Lazzari, Vincent (2016). "Molecular phylogeny of South-East Asian arboreal murine rodents". Zoologica Scripta. 45 (4): 349–364. doi:10.1111/zsc.12161. hdl:10072/101842. ISSN 1463-6409. S2CID 86285898.
  4. ^ a b c Database, Mammal Diversity (2021-11-06), Mammal Diversity Database, doi:10.5281/zenodo.5651212, retrieved 2021-12-11
  5. ^ a b Rowe, Kevin C.; Achmadi, Anang S.; Fabre, Pierre-Henri; Schenk, John J.; Steppan, Scott J.; Esselstyn, Jacob A. (2019). "Oceanic islands of Wallacea as a source for dispersal and diversification of murine rodents". Journal of Biogeography. 46 (12): 2752–2768. doi:10.1111/jbi.13720. ISSN 1365-2699. S2CID 208583483.
  6. ^ Roycroft, Emily; MacDonald, Anna J.; Moritz, Craig; Moussalli, Adnan; Miguez, Roberto Portela; Rowe, Kevin C. (2021-07-06). "Museum genomics reveals the rapid decline and extinction of Australian rodents since European settlement". Proceedings of the National Academy of Sciences. 118 (27): e2021390118. Bibcode:2021PNAS..11821390R. doi:10.1073/pnas.2021390118. ISSN 0027-8424. PMC 8271571. PMID 34183409.
  7. ^ Innis, Michelle (2016-06-14). "Australian Rodent Is First Mammal Made Extinct by Human-Driven Climate Change, Scientists Say". The New York Times. ISSN 0362-4331. Retrieved 2021-12-11.