Science and conservation for the world’s 2800 small mammal species

Rodents: Family Muridae

holding_imgThe family Muridae consists of rats, mice, and their relatives from the Old World, and currently includes 5 subfamilies. These subfamilies further diversified into 150 genera and 730 species from multiple radiations that occurred in Asia during the Miocene, making it the largest mammal group. Genetic evidence indicates that these radiations resulted in the five lineages of murids. The first subfamily is Deomyinae, an African and Asian group that includes the spiny mice. The subfamily Gerbillinae, gerbils and relatives, is found in arid regions of Africa through the Middle East and into Asia. These small mice share many arid-adaptations with other mammals like kangaroo rats and jerboas. The subfamily Leimacomyinae contains only a single species, the grooved toothed forest mouse, from tropical Africa. The Otomyinae contains the whistling rats and vlei rats restricted to sub-Saharan Africa. Finally, the subfamily Murinae contains 561 species of which are generically called Old World rats and mice. Though current evidence supports these subfamilies, relations within Muridae continue to be evaluated. Members of Muridae are native to Australia, Europe, Africa and Asia, including parts of Micronesia, but are found worldwide, except for Antarctica, as commensals. Murids ,therefore, occupy a great diversity of habitats such as tropical forests, wetlands, and deserts and can be semi-aquatic, fossorial, or terrestrial. Diets also vary, as species can be herbivorous, omnivorous, or carnivorous.   

Characteristics of murid skulls include an enlarged infraorbital foramen with a keyhole shape, a broad zygomatic plate, the lack of a postorbital process, and a sciurognathus lower jaw. In a sciurognathous jaw, the angular process and incisors begin at the same area. Each side of the jaw also includes one incisor each on the top and bottom rows, and does not include premolars. Most murids have three ever-growing molars. Shared physical characteristics include four claws on each front foot and five claws on the back feet. Other characteristics vary due to the different habitats populated by murids. Certain species of Muridae have historically carried diseases that devastate human and animal populations alike. Other species, however, maintain both insect populations and the quality of forests.



Work Cited
Myers, P. 2001. “Muridae Old World mice and rats, gerbils, whistling rats, and relatives” (Online). Animal Diversity Web. Accessed April 15, 2015 at
Michaux, J. et al. “Evolutionary History of the Most Speciose Mammals: Molecular Phylogeny of Muroid Rodents.” Mol Biol Evol 18.11 (2001): 2017-2031. Web. April 15, 2015.
Vaughan, T.A., Ryan, J.M. and Czaplewski, N.J. 2015.Mammalogy, 6th edition. Jones and Bartlett Learning, Burlington, MA.

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