The New Ireland forest rat (''Rattus sanila'') is a large

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 n ...

in the family Muridae. It is endemic to New Ireland, in the Bismarck Archipelago,

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 ...

Description

''Ratus sanila'' is known only by the discovery of some 7 subfossil fragments of jaw dated to over 3000 years old. The molars of this particular species are broad and have a very complex structure of the

cusp A cusp is the most pointed end of a curve. It often refers to cusp (anatomy), a pointed structure on a tooth. Cusp or CUSP may also refer to: Mathematics * Cusp (singularity), a singular point of a curve * Cusp catastrophe, a branch of bifurc ...

. The

diastema A diastema (plural diastemata, from Greek διάστημα, space) is a space or gap between two teeth. Many species of mammals have diastemata as a normal feature, most commonly between the incisors and molars. More colloquially, the condition ...

is also longer than in other species of the genus ''

Rattus ''Rattus'' is a genus of muroid rodents, all typically called rats. However, the term rat can also be applied to rodent species outside of this genus. Species and description The best-known ''Rattus'' species are the black rat (''R. rattus'') ...

'' suggesting a separate species which may be a relict of an archaic or ancestral dispersal of ''Rattus'' stock to New Guinea and Australia. This species probably still survives in some

primary forest An old-growth forestalso termed primary forest, virgin forest, late seral forest, primeval forest, or first-growth forestis a forest that has attained great age without significant disturbance, and thereby exhibits unique ecological feature ...

References

External links

*http://thewebsiteofeverything.com/animals/mammals/Rodentia/Muridae/Rattus/Rattus-sanila.html
Bucknell
*http://www.itis.gov/servlet/SingleRpt/SingleRpt?search_topic=TSN&search_value=585548 Rattus Rodents of Papua New Guinea Rodents of Australia Mammals described in 1991 {{murinae-stub