Rodentia
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. NODSCID, 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