Skull & Jaw Identification

↑Carnivore (Cat) vs Herbivore (Deer)↓Carnivore (Dog) vs Herbivore (Goat)

Some Questions to Ask …1. Do eyes (orbits) face forward (predator) or to the side (prey)?2. Is there a big gap (diastema) between the incisors/canines and

the rest of the teeth (if yes – herbivore)?3. Is the jaw joint at the same level as the teeth

(carnivore/omnivore) or is the jaw joint well above the level of the teeth (herbivore)?

4. Is it a long face with well-retracted nasals (some herbivores) or a short face (some carnivores)?

Dental Formula: 3, 1, 4, 23, 1, 4, 3

Upper Jaw: Incisors, Canines, Premolars, Molars Lower Jaw: Incisors, Canines, Premolars, Molars

Incisors - knife-edged for biting and cutting.Canines - pointed for puncturing and tearing.Premolars (bicuspids) - have two points for shearing and shredding.Molars - flattened for grinding and crushing.

Dental formula, lower jaw, and skull views of a coyote

Zygomatic Arch

Rostrum

Keying Skulls … before you start• Different books use different terms• Get a feel for how the animal made its living

by looking at placement of eyes, teeth, etc.• How big is the skull? Wide? Long?• What is the dental formula?• Often skulls or jaws are broken, with missing

teeth – remember that skulls are symmetrical.

• Smaller rodents are particularly hard to identify

• Look at range maps, know who is in your area.

• Remember that age plays a role in what you see (milk teeth versus permanent teeth, sutures on brain case, etc.)

Prepared by Gwen Heistand for ACR EducationSources/Diagrams: Pacific Coast Mammals by Russo & Olhausen; Animal Skulls by Richard S. White, Jr.; A Key-Guide to Mammal Skulls and Lower Jaws by Roest; Illustrated Key to Skulls of Genera of North American Land Mammals by Jones & Manning

grey fox

Dog family (Canidae)

Cat family (Felinidae)

Raccoon family (Procyonidae)

Order Carnivora

raccoonstriped skunk

Skunk family (Mephitidae)

mountain lion

long-tailed weasel

Weasel family (Mustelidae)

bobcat

Rodent Order (Rodentia)

Bat order (Chiroptera)

Order MarsupialiaMoles & Shrews order (Insectivora)

bat brush rabbit

Rabbit order (Lagomorph)

dusky-footed woodrat

Sonoma chipmunk

pocket gopher

Virginia opossumbroad-footed mole

Deer order (Artiodactyla)

mule deer

grey squirrel

If you find a small skull, without a diastema and with red-tipped teeth – you have the skull of a shrew. The shrew in our area is Trowbridge’s Shrew. (The enamel of the tips of their teeth is reddish due to iron pigment. The iron deposits serve to harden the enamel and are concentrated in those parts of the teeth most subject to wear.)

coyote

2,1,2,32,1,2,3

Human

Some skulls you may find (by order)(and a human skull)