Laotian rock rat

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Laotian rock rat
Laonastes aenigmamus - young male JP Hugot PLOS ONE.jpg

Laotian rock rat ( Laonastes aenigmamus )

Systematics
Superordinate : Euarchontoglires
Order : Rodents (Rodentia)
Subordination : Porcupine relatives (Hystricomorpha)
Family : Diatomyidae
Genre : Laonastes
Type : Laotian rock rat
Scientific name of the  family
Diatomyidae
Mein & Ginsburg , 1997
Scientific name of the  genus
Laonastes
Jenkins , Kilpatrick , Robinson & Timmins , 2005
Scientific name of the  species
Laonastes aenigmamus
Jenkins, Kilpatrick, Robinson & Timmins, 2005

The Laotian rock rat , laot. Kha-Nyou ( Laonastes aenigmamus ) is a species of rodent that was not scientifically described until 2005. It lives in Laos and Vietnam and is not closely related to any other living rodent species. It is the only recent member of the Diatomyidae family , the remaining members of which have been extinct for eleven million years.

description

The Laotian rock rat outwardly resembles a squirrel . The legs are short, the tail is hairy. The large, rounded skull and the characteristic waddling gait are striking. The fur of these animals is colored dark gray or black. They reach a head body length of around 26 centimeters, a tail length of 14 centimeters and a weight of around 400 grams.

Distribution and way of life

Laotian rock rats were originally only known from the province of Khammouan in southern Laos , where they live in a region of karstified limestone. In 2012 they were also detected in the Vietnamese national park Phong Nha-Ke Bang . They are believed to be nocturnal and feed on leaves, seeds, and grasses. They may also consume insects on a small scale .

They are classified as endangered by the IUCN .

Discovery story

The local population had known for a long time about the existence of these animals, which they called Kha-Nyou and hunted for their meat. At a market in Khammouan, Western scientists discovered the carcasses of these animals for the first time, which were then offered grilled for consumption. Morphological and DNA examinations showed that the animals are not closely related to any other rodent species. In 2005 they were given the scientific name Laonastes (= "rock dwellers") aenigmamus (= "enigmatic mouse").

In 2006 David Redfield , a professor emeritus from Florida State University , caught and filmed a live specimen for the first time. It turned out to be very trusting.

Systematics

After its discovery, the Laotian rock rat was placed in a new family, the Laonastidae. While new mammal species are regularly discovered, one new mammal family caused a sensation: the last newly discovered family was the pig-nosed bat ( Craseonycteris thonglongyai ), which forms the monotypic family of Craseonycteridae and was scientifically described in 1974. On the basis of morphological and genetic investigations, the Laotian rock rat was assigned to the subordination of porcupine relatives (Hystricomorpha), as their most primitive representative it was considered.

In 2006, Mary R. Dawson and others investigated relationships with fossil rodent taxa; it was discovered that these animals belong to the Diatomyidae, a group of rodents that had previously been considered extinct and whose previously known representatives lived in Asia from the early Oligocene (32 million years ago) to the Miocene (11 million years ago) . The appearance of a species believed to be extinct or a representative of a family believed to be extinct is known as the Lazarus effect .

The relationships of the Diatomyidae to other rodent taxa are still controversial. Genetic studies suggest a relationship to other ancient porcupine relatives such as the African rock rats or the sand graves . In contrast, Dawson argued that the lower jaw was similar to that of the squirrel relatives . A close relationship to the comb fingers was suggested, in other classifications the Diatomyidae are incorporated into the thorn-tailed squirrel relatives. In 2007, the close relationship to the comb fingers was again confirmed on the basis of a broader molecular biological analysis and the Laotian rock rat was identified as a sister species of the comb fingers, with the separation of the two taxa estimated at around 44 million years.

literature

  • Paulina D. Jenkins, C. William Kilpatrick, Mark F. Robinson, Robert J. Timmins: Morphological and molecular investigations of a new family, genus and species of rodent (Mammalia: Rodentia: Hystricognatha) from Lao PDR. In: Systematics and Biodiversity. Vol. 2, No. 4, 2005, ISSN  1477-2000 , pp. 419-454, doi : 10.1017 / S1477200004001549 .
  • Mary R. Dawson, Laurent Marivaux, Chuan-kui Li, K. Christopher Beard, Grégoire Métais: Laonastes and the “Lazarus Effect” in Recent Mammals. In: Science . Vol. 311, No. 5766, 10 March 2006, pp. 1456-1458, doi : 10.1126 / science.1124187 .

Individual evidence

  1. Nguyen Xuan Dang, Nguyen Xuan Nghia, Nguyen Manh Ha, Le Duc Minh, Nguyen Duy Luong, Dinh Huy Tri: The first record of living "Fossil" species (Laonestes aenigmanus) in Phong Nha - Ke Bang, Quang Binh province, Vietnam . In: Vietnam Journal of Biology 34 (1), 2012; Pp. 40-47.
  2. ^ A b c Paulina D. Jenkins, C. William Kilpatrick, Mark F. Robinson, Robert J. Timmins: Morphological and molecular investigations of a new family, genus and species of rodent (Mammalia: Rodentia: Hystricognatha) from Lao PDR. In: Systematics and Biodiversity. Vol. 2, No. 4, 2005, ISSN  1477-2000 , pp. 419-454, doi : 10.1017 / S1477200004001549 .
  3. ^ Mary R. Dawson, Laurent Marivaux, Chuan-kui Li, K. Christopher Beard, Grégoire Métais: Laonastes and the "Lazarus effect" in Recent Mammals. In: Science . Vol. 311, No. 5766, 10 March 2006, pp. 1456-1458, doi : 10.1126 / science.1124187 .
  4. Dorothée Huchon, Pascale Chevret, Ursula Jordan, C. William Kilpatrick, Vincent Ranwez, Paulina D. Jenkins, Jürgen Brosius, Jürgen Schmitz: Multiple molecular evidences for a living mammalian fossil. Proceedings of the National Academy of Sciences (PNAS) 104 (18), 2007; Pp. 7495-7499. doi : 10.1073 / pnas.0701289104 .

Web links

Commons : Laotian rock rat ( Laonastes aenigmamus )  - Collection of images, videos and audio files