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Laonastes

Laotian rock rat
Temporal range: Late Miocene-Recent
Laonastes aenigmamus - young male JP Hugot PLOS ONE.jpg
Young male
Scientific classification
Kingdom: Animalia
Phylum: Chordata
Class: Mammalia
Order: Rodentia
Family: Diatomyidae
Genus: Laonastes
Jenkins, Kilpatrick, Robinson & Timmins, 2005
Species: L. aenigmamus
Binomial name
Laonastes aenigmamus
Jenkins, Kilpatrick, Robinson & Timmins, 2005

The Laotian rock rat or kha-nyou (Latin: Laonastes aenigmamus, Lao: ຂະຍຸ), sometimes called the "rat-squirrel", is a rodent species of the Khammouan region of Laos. The species was first described in a 2005 article by Paulina Jenkins and coauthors, who considered the animal to be so distinct from all living rodents, they placed it in a new family, Laonastidae. It is in the monotypic genus Laonastes.

In 2006, the classification of the Laotian rock rat was disputed by Mary Dawson and coauthors. Dawson and her colleagues suggested instead it belongs to the ancient fossil family Diatomyidae, that was thought to have been extinct for 11 million years, since the late Miocene. It would thereby represent a Lazarus taxon. The animals resemble large, dark rats with hairy, thick tails like those of a squirrel. Their skulls are very distinctive and have features that separate them from all other living mammals.

Upon their initial discovery, Jenkins and coauthors (2005) considered the Laotian rock rat to represent a completely new family. The discovery of a new species of an extant mammal genus happens periodically, such as with the leaf muntjac or saola. The discovery of a completely new family is, by comparison, much more unusual. The most recent incident before the discovery of the family Laonastidae by Western science was the discovery of the bumblebee bat (Craseonycteris thonglongyai; family Craseonycteridae) in 1974. The only other examples from the 20th century are species that are only considered distinct families by a few authorities. These discoveries are: the Chinese river dolphin (Lipotes vexillifer; family Lipotidae) in 1918, the Zagros mouse-like hamster (Calomyscus bailwardi; family Calomyscidae) in 1905, and Goeldi's marmoset (Callimico goeldii; family Callimiconidae) in 1904. Representatives from all the remaining rodent families with living representatives (approximately 30) were discovered before 1900.


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Wikipedia

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