'' Baiyankamys'' is a genus of amphibious

murid In Sufism, a ''murīd'' (Arabic مُرِيد 'one who seeks') is a novice committed to spiritual enlightenment by ''sulūk'' (traversing a path) under a spiritual guide, who may take the title murshid, '' pir'' or ''shaykh''. A '' sālik'' or Su ...

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

s. It was originally described, along with the species ''

Baiyankamys shawmayeri Shaw Mayer's water rat (''Baiyankamys shawmayeri'') is a semiaquatic species of rodent in the family Muridae. It is found in the mountains of Papua New Guinea. Names It is known as kuypep kuykuy-sek in the Kalam language of Papua New Guinea ...

'' by Hinton in 1943 after he found the remains of a single individual in south east of the Bismarck Mountain Range, north east

New Guinea New Guinea (; Hiri Motu Hiri Motu, also known as Police Motu, Pidgin Motu, or just Hiri, is a language of Papua New Guinea, which is spoken in surrounding areas of Port Moresby (Capital of Papua New Guinea). It is a simplified version of ...

Tate Tate is an institution that houses, in a network of four art galleries, the United Kingdom's national collection of British art, and international modern and contemporary art. It is not a government institution, but its main sponsor is the U ...

, in 1951 and, Laurie and

Hill A hill is a landform that extends above the surrounding terrain. It often has a distinct Summit (topography), summit. Terminology The distinction between a hill and a mountain is unclear and largely subjective, but a hill is universally con ...

in 1954, confirmed the existence of both the species and genus. Crossomys-Baiyankamys-Hydromys

Classification

Hinton described '' Baiyankamys'' as similar in appearance to the species ''

Hydromys habbema The mountain water rat (''Baiyankamys habbema'') is a semiaquatic species of rodent in the family Muridae. It is found in West Papua, Indonesia and Papua New Guinea. Its natural habitat is river A river is a natural flowing watercours ...

'' but differed due to its unreduced

pinnae The auricle or auricula is the visible part of the ear that is outside the head. It is also called the pinna (Latin for "wing" or " fin", plural pinnae), a term that is used more in zoology. Structure The diagram shows the shape and location ...

and its lower teeth. It was described as having three lower molars on both sides of the lower jaw, whereas other genera of amphibious murines in New Guinea have only two. In 1968 Mahoney discovered that the specimen of ''B. shawmayeri'' was a composite resulting from an incorrectly associated mandible of the species '' Rattus niobe'' and the skull of a small water rat. When the correct mandible was found in the BMNH collections Mahoney proposed that, based on their similarity ''B. shawmayeri'' should be classified as a synonym of ''H. habbema''. However, Musser and Carleton (1993, 2005) and Flannery (1995) later proposed that the species Hinton described should be classified as ''

Hydromys shawmayeri Shaw Mayer's water rat (''Baiyankamys shawmayeri'') is a semiaquatic species of rodent in the family Muridae. It is found in the mountains of Papua New Guinea. Names It is known as kuypep kuykuy-sek in the Kalam language of Papua New Guinea ...

'', closely related but distinct from ''H. habbema'', based on the fact that they are easily distinguished by external and cranial traits,. In 2005 Helgen proposed that generic name of ''Baiyankamys'' be used for ''shawmayeri'' and ''habbema'', removing them both from the genus ''

Hydromys ''Hydromys'' is a genus (biology), genus of semiaquatic rodents in the subfamily Murinae. Three species are endemism, endemic to New Guinea and nearby islands. The fourth species, the rakali, is also found on Australia. The most recently discover ...

''. This was due to morphological differences in phallic anatomy, and many external and craniodental traits.

Appearance

''Baiyankamys'' is distinguished by soft, dense, frosted grey upperparts; a tail that is longer than its head-body length; a long, narrow

snout A snout is the protruding portion of an animal's face, consisting of its nose, mouth, and jaw. In many animals, the structure is called a muzzle, rostrum, or proboscis. The wet furless surface around the nostrils of the nose of many mammals is c ...

, and extremely narrow

incisors 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, wh ...

Habitat

''Baiyankamys habbema'' is found in a small region of the upper montane forests of the

Snow Mountains The Sudirman Range, also known as the Snow Mountains,"Sudirman Mountains (Snow Mountains)". Papua Insects Foundation. Accessed 5 August 2021/ref> Dugunduguoo, or Nassau Range is a mountain range in Central Papua province, Indonesia. It is named a ...

of western New Guinea, between 2800 and 3600 m. ''Baiyankamys shawmayeri'' is found in lower to upper montane forests between 1500 and 2600 m in eastern and central highlands regions of

Papua New Guinea Papua New Guinea (abbreviated PNG; , ; tpi, Papua Niugini; ho, Papua Niu Gini), officially the Independent State of Papua New Guinea ( tpi, Independen Stet bilong Papua Niugini; ho, Independen Stet bilong Papua Niu Gini), is a country i ...

References

External links

* * {{Taxonbar, from=Q141993 Rodent genera