Pseudohydromys germani
Encyclopedia
German's One-toothed Moss Mouse (Pseudohydromys germani) is a species of rodent
in the family Muridae
which occurs in the mountains of southeastern New Guinea
. It has only one molar
and only one incisor
in each jaw quadrant for a total of eight teeth
, less than any other rodents except for its close relative, the Small-toothed moss-mouse (P. ellermani). 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
, southeastern Papua New Guinea
in August 1992. P. germani was first described in 2005 by biologist Kristofer Helgen and named after Pavel German, who caught the specimen. 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
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
, P. germani is related to the False Water Rat
(Xeromys myoides) of Australia
and southern New Guinea and to the three species of Leptomys
, another New Guinean genus, and more distantly to other New Guinean and Australian rodents, including the Water Rat.
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.
Rodent
Rodentia is an order of mammals also known as rodents, characterised by two continuously growing incisors in the upper and lower jaws which must be kept short by gnawing....
in the family Muridae
Muridae
Muridae is the largest family of mammals. It contains over 600 species found naturally throughout Eurasia, Africa, and Australia. They have been introduced worldwide. The group includes true mice and rats, gerbils, and relatives....
which occurs in the mountains of southeastern New Guinea
New Guinea
New Guinea is the world's second largest island, after Greenland, covering a land area of 786,000 km2. Located in the southwest Pacific Ocean, it lies geographically to the east of the Malay Archipelago, with which it is sometimes included as part of a greater Indo-Australian Archipelago...
. It has only one molar
Molar (tooth)
Molars are the rearmost and most complicated kind of tooth in most mammals. In many mammals they grind food; hence the Latin name mola, "millstone"....
and only one incisor
Incisor
Incisors are the first kind of tooth in heterodont mammals. They are located in the premaxilla above and mandible below.-Function:...
in each jaw quadrant for a total of eight teeth
Tooth
Teeth are small, calcified, whitish structures found in the jaws of many vertebrates that are used to break down food. Some animals, particularly carnivores, also use teeth for hunting or for defensive purposes. The roots of teeth are embedded in the Mandible bone or the Maxillary bone and are...
, less than any other rodents except for its close relative, the Small-toothed moss-mouse (P. ellermani). 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 Province
Milne Bay is a province of Papua New Guinea. Its capital is Alotau. The province covers 14,000 km² of land and 252,990 km² of sea, within the province there are more than 600 islands, about 160 of which are inhabited...
, southeastern Papua New Guinea
Papua New Guinea
Papua New Guinea , officially the Independent State of Papua New Guinea, is a country in Oceania, occupying the eastern half of the island of New Guinea and numerous offshore islands...
in August 1992. P. germani was first described in 2005 by biologist Kristofer Helgen and named after Pavel German, who caught the specimen. 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
Pseudohydromys is a genus of rodent in the family Muridae.It contains the following species:* Bishop moss-mouse * Huon small-toothed moss-mouse...
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
Murinae
The Old World rats and mice, part of the subfamily Murinae in the family Muridae, comprise at least 519 species. This subfamily is larger than all mammal families except the Cricetidae and Muridae, and is larger than all mammal orders except the bats and the remainder of the...
, P. germani is related to the False Water Rat
False Water Rat
Xeromys myoides, the False Water-rat, is a species of rodent native to waterways of Australia and Papua New Guinea.-Description:False water rats have markedly long, flattened heads with small eyes and short, rounded ears. These rats possess just two molars on each side of the upper and lower jaw...
(Xeromys myoides) of Australia
Australia
Australia , officially the Commonwealth of Australia, is a country in the Southern Hemisphere comprising the mainland of the Australian continent, the island of Tasmania, and numerous smaller islands in the Indian and Pacific Oceans. It is the world's sixth-largest country by total area...
and southern New Guinea and to the three species of Leptomys
Leptomys
Leptomys is a genus of rodent from 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.-Species:* Leptomys arfakensis Musser, Helgen & Lunde, 2008...
, another New Guinean genus, and more distantly to other New Guinean and Australian rodents, including the Water Rat.
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.