Lamellar tooth rats
| Lamellar tooth rats | ||||||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|
South African lamellar tooth rat |
||||||||||||
| Systematics | ||||||||||||
|
||||||||||||
| Scientific name | ||||||||||||
| Otomys | ||||||||||||
| F. Cuvier , 1824 |
The lamellar tooth rats or African swamp rats ( Otomys ) are a genus of rodents from the group of old world mice (Murinae). They include around 20 species living in Africa.
features
Lamellar tooth rats reach a head body length of 12 to 21 centimeters, in addition there is a 6 to 15 centimeter long tail. Their weight is between 60 and 260 grams. Their fur is long and shaggy, its color varies from light gray to dark brown, the underside is lighter. The relatively short tail is densely hairy. Their bodies are stocky, their heads are rounded, they resemble voles . The name-giving feature is the lamellar molars , next to them there is a noticeable furrow on each of the incisor teeth .
distribution and habitat
These rodents are in Africa south of the Sahara is home, their range is from Nigeria and southern Sudan to South Africa . They occur in different habitats, but prefer more humid habitats. They can be found in swamps and grasslands, but sometimes also in savannahs and in mountainous regions up to an altitude of 4000 meters.
Way of life
Lamellar tooth rats can be active during the day and at night, but they can often be observed during twilight. Many species build nests out of leaves and twigs, others use holes in the ground as shelters. To get ahead faster, they create trails in the thick grass, and in the event of a threat they can also flee into the water. Most species are likely to live solitary or at most in pairs. They are herbivores that feed on grasses, herbs and other things.
The female can give birth to one to four young animals up to five times a year after a gestation period of around 40 days.
Several species are endangered, especially those whose range only includes a single mountain, such as Mount Elgon or the Cameroon Mountain . The IUCN lists four species as "vulnerable" ( vulnerable ) or ( "high risk" endangered ), but acknowledges not all species listed below.
Systematics
The lamellar tooth rats , together with the closely related genera Myotomys and Karru rats ( Parotomys ), form a group of species that were previously listed as a separate subfamily, Otomyinae. According to genetic studies, however, they are closely related to various African genus groups of Old World mice (Murinae), such as the Arvicanthis group, and are therefore also included in the Old World mice.
19 species are known (according to Carleton & Musser, 2005):
- Otomys anchietae lives in northern and central Angola.
- Otomys angoniensis is widespread in eastern and southern Africa.
- Otomys barbouri only inhabits the Mount Elgon volcano in the Ugandan-Kenyan border area. The species is considered "critically endangered".
- Otomys burtoni is only known from the Cameroon Mountain in Cameroon. This species is also "critically endangered".
- Otoyms cuanzensis occurs in central Angola.
- Otomys dartmouthi lives in the Ruwenzori Mountains in Uganda.
- Otomys denti lives in various mountainous countries in eastern Africa.
- Otomys dollmani is only known from Mount Gargues in Kenya.
- The South African lamellar tooth rat ( Otomys irroratus ) occurs in southern Africa.
- Otomys jacksoni lives on Mount Elgon in the Ugandan-Kenyan border area.
- Otomys lacustris lives in mountainous regions in eastern Africa. The species is considered "endangered".
- Otomys laminatus is native to South Africa.
- Otomys maximus lives in the Okavango region in southern Africa.
- Otomys occidentalis lives on mountains in the Nigerian-Cameroon border area. The species is considered "endangered".
- Otomys orestes occurs in Kenya and Tanzania.
- Otomys saundersiae is only found in South Africa.
- Otomys tropicalis is distributed from southern Sudan to the Democratic Republic of the Congo.
- Otomys typus lives in the mountainous region of Ethiopia up to an altitude of 4000 meters.
- Otomys uzungwensis lives in the Udzungwa Mountains in Tanzania.
literature
- Ronald M. Nowak: Walker's Mammals of the World . Johns Hopkins University Press, 1999 ISBN 0-8018-5789-9
- Michael D. Carleton, Guy G. Musser: Order Rodentia . In: Don E. Wilson, DeeAnn M. Reeder (Eds.): Mammal Species of the World . 3rd edition. The Johns Hopkins University Press, Baltimore 2005, pp. 745-752, ISBN 0-8018-8221-4 .
- SA Jansa and M. Weksler: Phylogeny of muroid rodents: relationships within and among major lineages as determined by IRBP gene sequences. In: Molecular Phylogenetics and Evolution, 31 (2004), pp. 256-276.
