German's one-toothed moss mouse (''Pseudohydromys germani'')Reeder, D.M., Helgen, K.M. & Wilson, D.E. 2007. Global trends and biases in new mammal species discoveries. Occasional Papers of the Museum of Texas Tech University 269. is a species of

rodent Rodents (from Latin , 'to gnaw') are mammals of the Order (biology), order Rodentia ( ), which are characterized by a single pair of continuously growing incisors in each of the upper and Mandible, lower jaws. About 40% of all mammal specie ...

in the family

Muridae The Muridae, or murids, are either the largest or second-largest family of rodents and of mammals, containing approximately 870 species, including many species of mice, rats, and gerbils found naturally throughout Eurasia, Africa, and Australia. ...

which occurs in the mountains of southeastern

New Guinea New Guinea (; Hiri Motu: ''Niu Gini''; , fossilized , also known as Papua or historically ) is the List of islands by area, world's second-largest island, with an area of . Located in Melanesia in the southwestern Pacific Ocean, the island is ...

Taxonomy

It was first described in the genus ''Mayermys'', but this genus, which only included the two one-molared species, has since been synonymised under ''

Pseudohydromys ''Pseudohydromys'' is a genus of rodents in the family Muridae endemic to New Guinea. It contains the following species: * Bishop's moss mouse (''Pseudohydromys berniceae'') * Huon small-toothed moss mouse (''Pseudohydromys carlae'') * Laur ...

'' because of the close morphological resemblances among ''Mayermys'' and the other species now placed in ''Pseudohydromys''. As a member of the ''Xeromys'' division within the subfamily

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 ...

, ''P. germani'' is related to the

false water rat ''Xeromys myoides'', also known as the water mouse, marine mouse, mangrove mouse, false water rat, manngay and yirrkoo, is a species of rodent native to waterways of Australia and Papua New Guinea. Taxonomy A description of the species was pu ...

(''Xeromys myoides'') of

Australia Australia, officially the Commonwealth of Australia, is a country comprising mainland Australia, the mainland of the Australia (continent), Australian continent, the island of Tasmania and list of islands of Australia, numerous smaller isl ...

and southern New Guinea and to the three species of ''

Leptomys ''Leptomys'' is a genus of rodent endemic to New Guinea. It is considered part of the New Guinea Old Endemics, meaning it was part of the first wave of murine rodents to colonize the island. ''Leptomys'' are seen to have minimal adaptations to ...

'', another New Guinean genus, and more distantly to other New Guinean and Australian rodents, including the water rat.Musser, 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.

Description

Like its relative, ''P. germani'' is a small, inconspicuous, shrew-like mouse, but it is slightly larger and has darker (dark grey as opposed to pale grey) ears and a sparsely haired tail with short hairs (the other species has more and longer hairs). Its molars, however, are even smaller (less than 1 mm) than the other species's tiny teeth. The upper incisors are proodont, but less so than in the one-toothed shrew mouse. The head-body length is 105 mm, the tail length 103 mm, the hindfoot length 21 mm, the ear length 12.6 mm and the weight 29.5 g. It has only one molar and only one

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, wher ...

in each jaw quadrant for a total of eight

teeth A tooth (: teeth) is a hard, calcified structure found in the jaws (or mouths) of many vertebrates and used to break down food. Some animals, particularly carnivores and omnivores, also use teeth to help with capturing or wounding prey, tear ...

, less than any other rodents except for its close relative, the one-toothed shrew mouse (''P. ellermani'') and the recently described ''

Paucidentomys ''Paucidentomys'' is a genus of rodents of a type commonly known as shrew-rats which was discovered in 2012 in a remote rainforest on the Indonesian island, Sulawesi. The genus is monotypic, consisting of the species ''Paucidentomys vermidax'', o ...

'', which lacks molars entirely.

Distribution and habitat

It is known from only one specimen, an adult male which was caught at an altitude of 1300 m in the village of Munimun,

Milne Bay Province Milne Bay is a province of Papua New Guinea. Its capital is Alotau. The province covers 14,345 km2 of land and 252,990 km2 of sea, within the province there are more than 600 islands, about 160 of which are inhabited. The province has ...

, southeastern

Papua New Guinea Papua New Guinea, officially the Independent State of Papua New Guinea, is an island country in Oceania that comprises the eastern half of the island of New Guinea and offshore islands in Melanesia, a region of the southwestern Pacific Ocean n ...

in August 1992. ''P. germani'' was first described in 2005 by biologist Kristofer Helgen and named after Pavel German, who caught the specimen.Helgen, K.M. 2005. A new species of murid rodent (genus ''Mayermys'') from south-eastern New Guinea. Mammalian Biology 70(1):61-67.

References

{{Taxonbar, from=Q1971769 Pseudohydromys Rodents of Papua New Guinea Mammals described in 2005 Rodents of New Guinea