What exactly is a rodent?

Question

What exactly is a rodent?

Answer 1

guinea pigs, hamsters, ferret, things like that.

Answer 2

The number one definition for a rodent is a mammal that has two pairs of ever-growing incisors used for gnawing, which are the front long chisel-shaped teeth.  One pair on the upper jaw and one pair on the lower jaw.  They are located in the order Rodentia.

Here is a picture of a rodent skull;

http://www.flickr.com/photos/atomicplayb...

An animal that is commonly called a rodent but isn't a rodent is a rabbit.  Rabbits actually have three pairs of incisors, they have an extra pair behind the first pair on the upper jaw.  For this they are not rodents, they are lagomorphs.

Lagomorph's second pair of incisors on the upper jaw;

http://www.flmnh.ufl.edu/fossilhall/Libr...

- Ferrets are not rodents, they are carnivores.  They have teeth like any other mammal of the Carnivora order.

http://www.boneclones.com/images/BC_055_...

Answer 3

Any member of the order Rodentia, which contains 50% of all living mammal species. Rodents are gnawing, mostly herbivorous, placental mammals. They have one pair of upper and one pair of lower, continuously growing, incisors. When the lower jaw is pulled back, the cheek teeth connect for grinding; when it is pulled forward and down, the incisors meet at the tips for gnawing. Rodent families include squirrels (Sciuridae); Old World mice (see mouse) and rats (Muridae); deer mice (see deer mouse), gerbils, hamsters, lemmings, muskrats, wood rats, and voles (Cricetidae); beaver (Castoridae); gophers (Geomyidae); guinea pigs (Caviidae); pocket mice (see pocket mouse) and kangaroo rats and mice (Heteromyidae); New and Old World porcupines (Erethizontidae and Hystricidae); and hutia (Capromyidae).

Answer 4

The number one definition for a rodent is a mammal that has two pairs of ever-growing incisors used for gnawing, which are the front long chisel-shaped teeth. One pair on the upper jaw and one pair on the lower jaw. They are located in the everywhere but the south pole. hear list below in the order Rodentia.

The rodents are part of the clades: Glires (along with lagomorphs), Euarchontoglires (along with lagomorphs, primates, treeshrews, and colugos), and Boreoeutheria (along with most other placental mammals). The order Rodentia may be divided into suborders, infraorders, superfamilies and families.

ORDER RODENTIA (from Latin, rodere, to gnaw)

Suborder Anomaluromorpha

Family Anomaluridae: scaly-tailed squirrels

Family Pedetidae: springhares

Suborder Castorimorpha

Superfamily Castoroidea

Family Castoridae: beavers

Superfamily Geomyoidea

Family Geomyidae: pocket gophers (true gophers)

Family Heteromyidae: kangaroo rats and kangaroo mice

Suborder Hystricomorpha

Family incertae sedis Diatomyidae: Laotian rock rat

Infraorder Ctenodactylomorphi

Family Ctenodactylidae: gundis

Infraorder Hystricognathi

Family Bathyergidae: African mole rats

Family Hystricidae: Old World porcupines

Family Petromuridae: dassie rat

Family Thryonomyidae: cane rats

Parvorder Caviomorpha

Family †Heptaxodontidae: giant hutias

Family Abrocomidae: chinchilla rats

Family Capromyidae: hutias

Family Caviidae: cavies, including guinea pigs and the capybara

Family Chinchillidae: chinchillas and viscachas

Family Ctenomyidae: tuco-tucos

Family Dasyproctidae: agoutis

Family Dinomyidae: pacaranas

Family Echimyidae: spiny rats

Family Erethizontidae: New World porcupines

Family Myocastoridae: nutria

Family Octodontidae: octodonts

Suborder Myomorpha

Superfamily Dipodoidea

Family Dipodidae: jerboas and jumping mice

Superfamily Muroidea

Family Calomyscidae: mouse-like hamsters

Family Cricetidae: hamsters, New World rats and mice, voles

Family Muridae: true mice and rats, gerbils, spiny mice, crested rat

Family Nesomyidae: climbing mice, rock mice, white-tailed rat, Malagasy rats and mice

Family Platacanthomyidae: spiny dormice

Family Spalacidae: mole rats, bamboo rats, and zokors

Suborder Sciuromorpha

Family Aplodontiidae: mountain beaver

Family Gliridae (also Myoxidae, Muscardinidae): dormice

Family Sciuridae: squirrels, including chipmunks, prairie dogs, & marmots