Rodentia

Superkingdom Eukaryota
Kingdom Animalia
Phylum Chordata
Subphylum Verterbrata
Class Mammalia
Order Rodentia

The largest order of mammals, having 34 families, about 389 genera, and more than 2000 species.  Rodents are recognizable from their paired large incisors.   The families are classified primarily by the forms of these incisors, as well as their jaws.

Notice that rabbits are not rodents; they belong to their own order, Lagomorpha.

Moles and Hedgehogs can be found in order Insectivora.

In the list of families below, I have placed each family's approximate number of genera and species in parentheses after the family name (#genera, #species)

Suborder Sciurognatha

• Infraorder Anamolomorpha aka Theridomorpha
  • Family Anomaluridae (scaly-tailed squirrels) (4, 12)
  • Family Pedetidae (springhaas) (1, 2)
• Infraorder Castorimorpha
  • Family Castoridae (beaver) (1, 2)
• Infraorder Ctenodactylomorpha
  • Family Ctenodactylidae (4, 8)
• Infraorder Glirimorpha
• Family Gilridae aka Myoxidae (dormice) (4, 23)
• Infraorder Myomorpha
  • Family Cricetidae (gerbils, hamsters, mice, New World rats, and voles) (?, 570) Often merged with the Muridae.
  • Family Dipodidae (Birch mice, jumping mice, jerboa) (15, 51)
  • Family Geomyidae (pocket gophers) (6 ,36)
  • Family Heteromyidae (kangaroo rat, kangaroo mouse, pocket mouse) (6, 59)
  • Family Muridae (Old World rats and mice)
  • Family Platacanthomyidae (spiny dormice)
  • Family Rhizomyidae (bamboo rats)
  • Family Seleviniidae
  • Family Spalacidae (Eurasian mole rats)
  • Family Zapodidae (jumping mice)
• Infraorder Protrogomorpha
  • Family Aplodontidae ('mountain beaver') (1, 1)
• Infraorder Sciuromorpha
  • Family Sciuridae (chipmunks, marmots, prarie dogs, squirrels, and woodchucks) (50, 260)
  • Some researchers place Geomyidae and Hetermyidae here.

• Infraorder Bathyergomorpha
  • Family Bathyerigidae (Subsaharan Africa mole rats) (?, 22)
• Infraorder Caviomorpha
  • Some researchers place Agoutis in their own family, Agoutidae
  • Family Abrocomidae (chinchilla rats)
  • Family Capromyidae (some put nutria here)
  • Family Cavidae (cavies, aka "guinea pigs") (3, 12)
  • Family Chinchillidae (chinchillas) (?, 6)
  • Family Ctenomyidae (?, 26)
  • Family Dasyproctidae (agoutis, pacas) (?, 11)
  • Family Dinomyidae (1, 1)
  • Family Echimyidae (spiny rats) (?, 43)
  • Family Erethizontidae (New World porcupines) (?, 8)
  • Family Heptaxodontidae
  • Family Hydrochoeridae (capybaras)
  • Family Myocastoridae (nutria)
  • Family Octodontidae (hedge rats) (?, 8)
• Infraorder Hystricomorpha
  • Family Hystricidae (Old World porcupines)
• Infraorder Phiomorpha
  • Family Petromyidae (dassies) (1, 1)
  • Family Thryonomyidae (cane rats) (?, 6)

Mammals of Ohio
http://www4.wittenberg.edu/academics/biol/courses/mammals/Ohio.html

Tree of life web project
http://tolweb.org/tree/eukaryotes/animals/chordata/mammalia/rodentia/rodentia.html

Animals on the net
http://www.uni-hohenheim.de/~bahagish/index.html

Marc Robinson, Diversite des Modes D'evolution des Genomes de Rongeurs, (Ph.D. dissertation), page 15
http://biomserv.univ-lyon1.fr/txtdoc/THESES/ROBINSON/TheseROBM.pdf

Dr. George Atkins, GWU, Mammalian Order Rodentia
http://gwis2.circ.gwu.edu/~atkins/newwebpages/Mammalia/rodentia/rodentia.html

Ro*den"ti*a (?), n. pl. [NL. See Rodent, a.] Zool.

An order of mammals having two (rarely four) large incisor teeth in each jaw, distant from the molar teeth. The rats, squirrels, rabbits, marmots, and beavers belong to this order.

⇒ The incisor teeth are long, curved, and strongly enameled on the outside, so as to keep a cutting edge. They have a persistent pulp and grow continuously.

© Webster 1913.