The Togo mouse (''Leimacomys buettneri''), also known as Büttner's African forest mouse or the groove-toothed forest mouse, is a unique

muroid rodent The Muroidea are a large superfamily of rodents, including mice, rats, voles, hamsters, lemmings, gerbils, and many other relatives. Although the Muroidea originated in Eurasia, they occupy a vast variety of habitats on every continent except ...

known from only two specimens taken from near the type locality of Bismarckburg, near Yege, Togo, in 1890. Its

genus Genus ( plural genera ) is a taxonomic rank used in the biological classification of extant taxon, living and fossil organisms as well as Virus classification#ICTV classification, viruses. In the hierarchy of biological classification, genus com ...

monotypic In biology, a monotypic taxon is a taxonomic group (taxon) that contains only one immediately subordinate taxon. A monotypic species is one that does not include subspecies or smaller, infraspecific taxa. In the case of genera, the term "unispec ...

Description and natural history

The entirety of known material for this species consists of a single, poor-quality dry skin, a fluid-preserved animal, and a cranium and mandible. The cranium and mandible are from different animals. The material is deposited in the Zoologisches Museum of

Humboldt University Humboldt-Universität zu Berlin (german: Humboldt-Universität zu Berlin, abbreviated HU Berlin) is a German public research university in the central borough of Mitte in Berlin. It was established by Frederick William III on the initiative of ...

Berlin Berlin ( , ) is the capital and largest city of Germany by both area and population. Its 3.7 million inhabitants make it the European Union's most populous city, according to population within city limits. One of Germany's sixteen constitue ...

, Germany. The head and body length is with a tail of . This tail is unusually short relative to the body length (ratio of 37%) and is considered an important diagnostic feature. The animal is dark to grey brown above and pale grey brown below. Ears are small and hairy. Feet are also somewhat hairy. The tail may be naked or slightly haired. The

incisor Incisors (from Latin ''incidere'', "to cut") are the front teeth present in most mammals. They are located in the premaxilla above and on the mandible below. Humans have a total of eight (two on each side, top and bottom). Opossums have 18, whe ...

s are shallowly grooved. The snout is long and wide, the interorbital width is broad, and the

zygomatic plate In rodent anatomy, the zygomatic plate is a bony plate derived from the flattened front part of the zygomatic arch (cheekbone). At the back, it connects to the front (maxillary) root of the zygomatic arch, and at the top it is connected to the ...

is large). Based on skull morphology, the Togo mouse is presumed to be insectivorous. Very little is known about the

habits A habit (or wont as a humorous and formal term) is a routine of behavior that is repeated regularly and tends to occur subconsciously.

of this unusual mouse.

Classification

''Leimacomys'' has been transferred back and forth between the

Dendromurinae Dendromurinae is a subfamily of rodents in the family Nesomyidae and superfamily Muroidea. The dendromurines are currently restricted to Africa, as is the case for all extant members of the family Nesomyidae. The authorship of the subfamily has ...

and the

Murinae The Old World rats and mice, part of the subfamily Murinae in the family Muridae, comprise at least 519 species. Members of this subfamily are called murines. In terms of species richness, this subfamily is larger than all mammal families excep ...

since its discovery. It most closely resembles '' Lophuromys'', which has been transferred to a newly erected

Deomyinae The subfamily Deomyinae consists of four genera of mouse-like rodents that were placed in the subfamilies Murinae and Dendromurinae until very recently. They are sometimes called the Acomyinae, particularly in references that antedate the disc ...

on the basis of

molecular A molecule is a group of two or more atoms held together by attractive forces known as chemical bonds; depending on context, the term may or may not include ions which satisfy this criterion. In quantum physics, organic chemistry, and bioche ...

data. The association with ''Lophuromys'' is thought to be due to

convergent evolution Convergent evolution is the independent evolution of similar features in species of different periods or epochs in time. Convergent evolution creates analogous structures that have similar form or function but were not present in the last com ...

due to similar diets. Tooth characters resemble dendromurines, ''

Mystromys The white-tailed rat (''Mystromys albicaudatus'') also known as the white-tailed mouse, is the only member of the subfamily Mystromyinae in the family Nesomyidae. This species is sometimes placed in the subfamily Cricetinae due to similarities ...

'' or basal

gerbil The Mongolian gerbil or Mongolian jird (''Meriones unguiculatus'') is a small rodent belonging to the subfamily Gerbillinae. Their body size is typically , with a tail, and body weight , with adult males larger than females. The animal is use ...

s. Denys et al. generated a phylogeny that suggested, with limited support, ''Leimacomys'' is a

sister taxon In phylogenetics, a sister group or sister taxon, also called an adelphotaxon, comprises the closest relative(s) of another given unit in an evolutionary tree. Definition The expression is most easily illustrated by a cladogram: Taxon A and t ...

to the

Gerbillinae Gerbillinae is one of the subfamilies of the rodent family Muridae and includes the gerbils, jirds, and sand rats. Once known as desert rats, the subfamily includes about 110 species of African, Indian, and Asian rodents, including sand rats a ...

. Musser and Carleton chose to erect a new subfamily, Leimacomyinae, to house this species. They placed it in the family

Muridae The Muridae, or murids, are the largest family of rodents and of mammals, containing approximately 1,383 species, including many species of mice, rats, and gerbils found naturally throughout Eurasia, Africa, and Australia. The name Muridae come ...

due to its potential connection to either the Gerbillinae or Deomyinae, but emphasized that a broad phylogenetic study including ''Leimacomys'', and a host of nesomyids and murids, is needed to determine its appropriate position.

Conservation status

The Togo mouse is considered to be either critically endangered or

extinct Extinction is the termination of a kind of organism or of a group of kinds (taxon), usually a species. The moment of extinction is generally considered to be the death of the last individual of the species, although the capacity to breed and ...

depending on the authority. Schlitter classified it as

, because subsequent surveys to the area failed to recover it. Grubb et al. (1998) noted these surveys inadequately sampled appropriate

habitat In ecology, the term habitat summarises the array of resources, physical and biotic factors that are present in an area, such as to support the survival and reproduction of a particular species. A species habitat can be seen as the physical ...

in Togo and neighboring

Ghana Ghana (; tw, Gaana, ee, Gana), officially the Republic of Ghana, is a country in West Africa. It abuts the Gulf of Guinea and the Atlantic Ocean to the south, sharing borders with Ivory Coast in the west, Burkina Faso in the north, and To ...

, and they were reluctant to declare the species extinct. Musser and CarletonMusser, G. G. and M. D. Carleton. 2005. Superfamily Muroidea. Pp. 894-1531 ''in'' Mammal Species of the World a Taxonomic and Geographic Reference. D. E. Wilson and D. M. Reeder eds. Johns Hopkins University Press, Baltimore. also emphasized the insectivorous muroids as a group have proven difficult to capture, and intense surveys of high-elevation forests in this region are required to determine if it still persists. The

IUCN The International Union for Conservation of Nature (IUCN; officially International Union for Conservation of Nature and Natural Resources) is an international organization working in the field of nature conservation and sustainable use of natu ...

currently describes the Togo mouse as "data deficient".

Description and natural history

Classification

Conservation status

References

Further reading