Rodentia

The single largest group of mammals is the rodentia. Most non-flying mammals are rodents. There are about 1500 living species of rodents (out of 4000 species of mammals).

Rodentia Most people are familiar with mice, rats, hamsters, and guinea pigs. Rodentia also includes beavers, muskrats, porcupines, woodchucks, chipmunks, squirrels, prairie dogs, and chinchillas. Rodentia does NOT include rabbits (they are different from rodents in that they have an extra pair of incisors and other different skeletal features).

Rodentia Rodents are found native on all continents except Antarctica. One family of rodents, the Muridae, contains over 1100 species. These are mice and rats.

Rodentia Rodents show their greatest diversity in South America. Some of these include: –mountain viscachas (which are rabbit-like animals that live in the moutains) –Patagonian cavies (which are rabbit-like, fast-running animals with long ears and a short tail) – the coypu (which is a marsh-dwelling animal that is hunted for its fur), –burrowing animals like the pacas and tuco-tuco.

Mountain viscachas

Patagonian cavies

Coypu

Paca

Tuco-tuco

Rodent The capybara, which also lives in South America, is the largest living rodent. It is about the size of a pig and gets up to a weight of about 110 pounds. They live in the plains of South America and are often hunted or ranched for their meat.

Capybaras

Rodent All rodents share common features. They have a single pair of incisors in each jaw, and they grow continually throughout life. The incisors have thick enamel layers on the front but not on the backs; this causes them to retain their chisel shape as they are worn down.

Rodent Behind the incisors is a large gap in the tooth rows, or diastema. There are no canines, and typically only a few molars at the rear of the jaws. Rodents have unique chewing patterns and they also have large jaw muscles to help with this.

Rodent Male rodents have a baculum, which is a penis bone. Most rodents are herbivores, but some are omnivores while others eat only insects. Rodents live in many different places, such as trees and burrows. They can also be found in some aquatic habitats and also in the desert. They can be solitary, like the porcupine, or live in highly-social groups, like prairie dogs.

Rodent Rodents cost billions of dollars in lost crops each year. Some are also carriers of human disease such as bubonic plague, typhus, and Hanta fever. Some rodent species are economically important as sources of food or fur. Others are used extensively in biochemical research (ie. NOD- SCID, C57-Bl6, and nude mice).

Eastern Chipmunk Tamias striatus

Gray Squirrel Sciurus carolinensis

Beaver Castor canadensis

Alabama Beach Mouse Peromyscus polionotus ammobates

Black Rat Rattus rattus

Mouse

Rat

Squirrel

Chipmunk

Vole

Kangaroo Rat

Gopher

Porcupine

Beaver

Hamster

Lemming

Jerboa

Gerbil

Guinea Pig

Chinchilla

Prairie Dog

Pocket Mice

Mole Rat

Groundhog

Capybara

Marmot

Muskrat