''Petromyscus'' is a genus of

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 ...

in the family

Nesomyidae The Nesomyidae are a family of African rodents in the large and complex superfamily Muroidea. It includes several subfamilies, all of which are native to either continental Africa or to Madagascar. Included in this family are Malagasy rodents, ...

. It is so distinct from other rodents that it is placed as the only genus in subfamily Petromyscinae. In previous classifications, '' Delanymys brooksi'' has also been placed in the subfamily. They are found in southwestern

Africa Africa is the world's second-largest and second-most populous continent, after Asia in both cases. At about 30.3 million km2 (11.7 million square miles) including adjacent islands, it covers 6% of Earth's total surface area ...

. These animals have a sharp lower point to their V-shaped infraorbital canal. Their molars are intermediate between the ancestral cricetid style tooth and the dendromurine style tooth. The genus contains the following species: * Barbour's rock mouse (''Petromyscus barbouri'') * Pygmy rock mouse (''Petromyscus collinus'') * Brukkaros pygmy rock mouse (''Petromyscus monticularis'') *

Shortridge's rock mouse Shortridge's rock mouse (''Petromyscus shortridgei'') is a species of rodent in the family Nesomyidae. It is found in Angola and Namibia. Its natural habitat is subtropical or tropical dry shrubland. References

* Petromyscus Mammals desc ...

(''Petromyscus shortridgei'')

References

*Jansa, S. A., S. M. Goodman, and P. K. Tucker. 1999.

Molecular phylogeny Molecular phylogenetics () is the branch of phylogeny that analyzes genetic, hereditary molecular differences, predominantly in DNA sequences, to gain information on an organism's evolutionary relationships. From these analyses, it is possible to ...

and

biogeography Biogeography is the study of the distribution of species and ecosystems in geographic space and through geological time. Organisms and biological communities often vary in a regular fashion along geographic gradients of latitude, elevation, ...

of the native

s of

Madagascar Madagascar (; mg, Madagasikara, ), officially the Republic of Madagascar ( mg, Repoblikan'i Madagasikara, links=no, ; french: République de Madagascar), is an island country in the Indian Ocean, approximately off the coast of East Africa ...

(

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 ...

Nesomyinae The Malagasy rodents are the sole members of the subfamily Nesomyinae. These animals are the only native rodents of Madagascar, come in many shapes and sizes, and occupy a wide variety of ecological niches. There are nesomyines that resemble ge ...

): a test of the single origin hypothesis. Cladistics, 15:253-270. *Jansa, S. A. and M. Weksler.

Phylogeny A phylogenetic tree (also phylogeny or evolutionary tree Felsenstein J. (2004). ''Inferring Phylogenies'' Sinauer Associates: Sunderland, MA.) is a branching diagram or a tree showing the evolutionary relationships among various biological spec ...

muroid 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 A ...

s: relationships within and among major lineages as determined by IRBP

gene In biology, the word gene (from , ; "...Wilhelm Johannsen coined the word gene to describe the Mendelian units of heredity..." meaning ''generation'' or ''birth'' or ''gender'') can have several different meanings. The Mendelian gene is a ba ...

sequences. Molecular Phylogenetics and Evolution, 31:256-276. *Kingdon, J. 1997. The Kingdon Field Guide to African Mammals. Academic Press Limited, London. * *Nowak, R. M. 1999. Walker's

Mammal Mammals () are a group of vertebrate animals constituting the class Mammalia (), characterized by the presence of mammary glands which in females produce milk for feeding (nursing) their young, a neocortex (a region of the brain), fur or ...

s of the World, Vol. 2. Johns Hopkins University Press, London. *Steppan, S. J., R. A. Adkins, and J. Anderson. 2004. Phylogeny and divergence date estimates of rapid radiations in muroid rodents based on multiple nuclear genes. Systematic Biology, 53:533-553. Rodent genera Taxa named by Oldfield Thomas Taxonomy articles created by Polbot {{muroid-stub