Order Rodentia

Order Rodentia

1) largest mammalian order ~3000 spp.

2) only 2 pairs of incisors, no canines - diastema always present

3) most nocturnal, some hibernate, some estivate during summer

Family Sciuridae

a) 4 toes on front feet, 5 on back

b) diurnal except for flying squirrels

c) tail typically furred

Example:

1) Marmota monax - Woodchuck
Skin: uniformly brown, fur frosted, feetdark brown, bushy tail
Skull: I 1/1 C 0/0 PM 2/1 M 3/3 Tot = 22
sagittal crest, incisors white

2) Tamias striatus - Eastern chipmunk
Skin: white stripe bordered by black onside of body
Skull: I 1/1 C 0/0 PM 1/1 M 3/3 Tot = 20

3) Sciurius niger - Fox squirrel
Skin: large bushy tail, fur tipped with yellow

4) Sciurius carolinensis - Gray squirrel
Skin: flattened tail, gray with silver tips
Sciurius skull characteristics:
Larger than Tamias but with same dental formula

5) Glaucomys saberinus - Northern flying squirrel
Skin: belly hair white, lead color at base

6) Glaucomys volans - Southern flying squirrel
Skin: belly hairs white to base.
Glaucomys Skull: I 1/1 C 0/0 PM 2/1 M 3/3 Tot = 22

7) Tamiasciurius hudsonicus - Red squirrel
Skin: uniformly yellow-reddish, small size
Skull: same formula as Sciurius but smaller

Family Muridae - Old World rats

a) long tails, scaly

b) molariform teeth having 3 rows of cusps
        (New world rats and mice have 2 rows of cusps)

c) active all year, primarily nocturnal

Example:

1) Rattus rattus - Black rat
Skin: brown to gray above, pale but not white below.
Tail scale and uniformly dark, tail longer than head and body.

2) Rattus norvegicus - Norway rat
Skin: grayish - brown color, belly pale
long tail but not longer than head and body
Rattus Skull: I 1/1 C 0/0 PM 0/0 M 3/3 Tot = 16

3) Mus musculus
Skin: grayish with gray-buff belly, scaly tail, small size
Skull: same formulas as Rattus but much smaller. Notched incisor tooth.

Family Geomyidae

a) found only in North America - burrowers

b) large external fur-lined cheek pouches

c) lips close behind incisors (helps keep dirt out of mouth)

d) 2 kinds of burrows -
        1) near surface for food gathering
        2) deeper for storage and shelter

Example

1) Geomys pinetis - Southeastern pocket gopher
Skin: distinct external cheek pockets. Short, nearly naked tail
Skull: two distinct grooves in upper incisors

Family Zapodidae

a) yellow or reddish in color - long tails to large hind feet

b) primarily nocturnal, long hibernators (6-8 months)

c) upper incisors grooved

Example:

1) Zapus hudsonius - Meadow jumping mouse
Skin: yellow sides, brown back, long tail with tip usually not white
Skull: I 1/1 C 0/0 PM 1/0 M 3/3 Tot = 18

2) Napaeozapus insignis
Skin: orange/yellow sides, brown back, long tail with white tip
Skull: I 1/1 C 0/0 PM 0/0 M 3/3 Tot = 16

Family Cricitidae

a) Dental structures:
        1) cricetines - teeth with well developed cusps, long tails, large                  eyes and ears
        2) microtines - voles and lemmings - teeth with flattened crowns                  with loop or triangular shaped ridges.

b) Most breed throughout year

Example:

1) Ondatra zibethicus - Muskrat
Skin: large size, long scaly tail that is flattened dorso-ventrally. Hind feet partially webbed.
Skull: I 1/1 C 0/0 PM 0/0 M 3/3 Tot = 16
large size triangular shaped cusps, no groove on incisors

2) Neofiber alleni - Round tailed muskrat
Skin: smaller, uniform color, tail long, scaly and round.
Skull: same formula as Ondatra

3) Peromyscus leucopus - White-footed mouse
Skin: upper brown, lower white. Tail shorter than head and body, bicolor.

4) Peromyscus polionotus - Old field mouse
Skin: pale color, tail short and banded

5) Peromyscus gossypinus - Cotton mouse
Skin: tail short-haired, less than head and body length

6) Peromyscus maniculatus - Deer mouse
Skin: tail distinctly bicolored, longer than head and body, and short-haired
Peromyscus Skull: I 1/1 C 0/0 PM 0/0 M 3/3 Tot = 16
2 rows of cusps on teeth, no triangular ridges.

7) Ochrotomys nuttali - Golden mouse
Skin: golden cinnamon above, white below, tail long.

8) Reithrodontomys humulis - Eastern harvest mouse
Skin: brown with dark middorsal strip, tail 1/2 total length and not distinctly bicolored
Skull: upper incisors grooved.

9) Microtus pinetonium - Woodland vole
Skin: reddish brown - short soft fur
tail short (~length of hind foot)

10) Microtus chrotorrhinus - Rock vole
Skin: relatively long tail, nose organish in color

11) Microtus pennsylvanicus - Meadow vole
Skin: Fur usually gray with silver tipped hair on belly.
Tail long and bicolored.
Microtus Skull: some have a grooved incisors, triangular ridges on cusps.

12) Clethrionomys gapperi - Southern red-backed vole
Skin: rust-red above, buff-white below
tail short, slightly bicolored
Skull: no grooves on upper incisors

13) Neotoma floridana - Eastern woodrat
Skin: grayish brown with whitish belly
tail shorter than head and body and furred.
Skull: incisors not grooved, large size loop shaped ridges on molars

14) Oryzomys palustris - Marsh rice rat
Skin: long scaly tail - bicolor, feet whitish
Skull: incisors not grooved, 2 row of cusps.
Larger than Peromyscus

15) Synaptomys cooperi - Southern Bog lemming
Skin: brown above, silver below, very short tail-bicolored
Skull: upper incisors shallowly grooved.

Order Carnivora

Order Chiroptera

Order Insectivora

Order Lagomorpha

Order Marsupial