When using skulls in education, the first question usually asked is "What kind of skull is that"? Skull identification can be determined by several methods. If you are unsure of a skull's identification, you can compare it with other known specimens. This, however, can be less than accurate and most will not have access to a large collection of known species. The most effective means of identifying a skull to species is with the use of a dichotomous key. A dichotomous key allows a person, through a series of questions, to identify an organism to species by process of elimination. Plants, fish and even skulls can be identified using this method. Below is an example of a dichotomous skull key.

Excerpt taken from "A Key-Guide To Mammal Skulls And Lower Jaws" by Aryan I Roest.


a. Large skull, over 150mm (6") long: go to step ---------- 2

b. Medium skull, 75-150mm (3-6") long: go to step ------ 19

c. Small skull, 25-75mm (1-3") long: go to step ---------- 32

d. Tiny skull, less than 25mm (1") long: go to step ------ 47


a. Orbit (eye socket) closed at back by a bony bar formed of fused postorbital process; no canines, OR canines about same size, or smaller than cheek teeth: ------------ 3

b. Orbit open at back; canines large, prominent: --------- 10

3. a. Skull over 300mm (1 foot) long: -------------------------- 4

b. Skull less than 300mm long: ------------------------------ 7

Etc., Etc., Etc.

A skull key can be a valuable teaching aid in the classroom. Skulls Unlimited carries several levels of key guides from simple to advanced. Keys come with convenient skull diagrams and a glossary explaining the anatomical terms used. To view other skull keys, Click Here.

Below are images of typical carnivore (bobcat), omnivore (raccoon) and herbivore (beaver) skulls. Various parts of each skull have been labeled to aid in comparative anatomy. These images may also prove to be useful in locating skull parts for dichotomous key identification. These images are free for educational use in the classroom. To view a high resolution, printable version, click on each image. Commercial use of these images is prohibited.

Bobcat Skull

Racoon Skull


Beaver Skull