Download Skull Identification – Natural Science

Skull Identification – Natural Science
What Can Skulls Tell Us?
Have you ever found a skull in the woods and wondered, "What kind
of animal was this?" or, "I wonder what this animal ate?" or "How
did this animal die?" Skulls can answer all of these questions…if you
know how to "read" them. Like the pages of a book may be read to
reveal the life of a man, so may a skull be "read" to reveal the
history and lifestyle of an animal. If you know what to look for, you
can interpret information about how the animal lived its life and
possibly, even how it died. Below we will illustrate how to "read" a
mammal skull.
Teeth
Mammals, as well as some reptiles, amphibians and fish, have teeth.
The teeth of an animal can tell you a lot about that animal's life.
The type, shape and number of teeth an animal has can help
determine its diet. If a mammal has long, sharp canines, it was
most likely a predator. Canines are used for grabbing, holding and
killing prey. Some meat eating mammals (carnivores) have sharp
shearing cheek-teeth called carnassials. These teeth act like a
scissor to cut through tough flesh and to break it into smaller
pieces for swallowing and digestion. Examples of carnivores include
cats, dogs and weasels.
Plant eating animals tend to have teeth specialized in chewing
various parts of plants. Some plant eaters eat grasses (grazers),
some eat twigs, leaves and berries (browsers) while others eat only
specific plant parts (I.e. roots, fruit, etc.). In order to properly
digest vegetation, an animal must chew its food to help break down
the plant. Most herbivores have cheek teeth called molars. These
molars help grind leaves, stems, grasses, fruit and even seeds
before the animal swallows them. Examples of herbivores include
deer, rabbits and cattle.
Some animals eat both plants and animals (omnivores) and have
both types of teeth. Examples of omnivores include pigs, bears and
humans
Beaks
The beak of a bird is an extension of its skull and is designed for
feeding. Some beaks have evolved to specialize in feeding specific
items. A duck, hawk, hummingbird and sparrow are all birds, but
their beaks are very different due to their different diet. A duck
has a wide flattened "bill" used for eating aquatic plants and
mosses. A hawk has a sharp hooked beak used in tearing flesh from
its prey or carrion. A hummingbird uses its long narrow beak to lap
nectar from flowers and a sparrow has a small powerful beak used
for picking berries and cracking seeds. As you can see, a bird's
beak can tell you a lot about not only the diet, but also the lifestyle
of its owner.
Eye Placement and Size
What do the eye sockets of a skull tell you about an animal? A lot!
Eye sockets that are large in relation to the size of an animal's
skull may suggest an animal is active at night (nocturnal). In this
case, a larger eye hasevolved to allow the animal to see better at
night.Eyes that face forward on a skull suggest a predator.
Forward facing eyes allow for binocular or stereoscopic vision,
which allows an animal to see andjudge depth. Predators need this
depth perception to track and pursue prey.Cats and owls are
excellent examples of predators that use forward facing eyes
when hunting their prey. Monkeys also have forward facing eyes
that give them depth perception needed to swing and leap in their
tree top habitat. Humans have forward facing eyes as well.
Animals with eyes that are located on the side of its head would
suggest a
prey animal. Side eye placement allows for greater peripheral or
side vision.This enables the animal to see predators approaching
from the side as well as from behind. This vision is very important
for protecting an animal when it is grazing or feeding.
"Eyes in the front, the animal hunts. Eyes on the side, the animal
hides."
Horns and Antlers
Horns or antlers found on a skull bear evidence of how an animal
communicated, defended it's self and possibly the animals sex.
Animals can protect themselves or attack other animals by goring
them with their horns or antlers. Bighorn sheep, muskox and deer
use their horns or antlers for establishing territory and winning
mates.
What is the difference between horns and antlers? Horns
are permanent structures that grow year after year. Depending on
the species, both male and female bovid animals (cattle, gazelle,
antelope, etc.) can have horns. Antlers, however, are temporary.
Antlers grow, develop and shed from the animal once a year.
Antlers are branched and only found in the cervid family (deer,
moose, elk, etc.). With the exception of the female caribou, only
male cervids have antlers.
Nasal Passages
The relative size of the nasal passage in a skull is an indication of
the animal’s sense of smell. The thin bony structures inside the
nasal passage (nasal turbinates) provide the framework for
membranes which sense odor. The greater the size of these
structures the greater the sense of smell. The short nasal
passages of cat skulls tell us that cats do not have a very good
sense of smell when compared with many other animals and rely
more on other senses to locate prey. Conversely, the long nasal
passage of a coyote indicates that coyotes have a very keen sense
of small and that this sense is important to the coyote’s survival.
Auditory Bullae
The auditory bullae (“bully”) are the bony portions of a skull that
encase structures of the inner and middle ear. In general, the
larger, the more inflated this structure, the greater the sense of
hearing. Cats have comparatively large, inflated auditory bullae
and very acute hearing. Although their hearing is much better
than a human’s, deer and elk have a relatively poor sense of hearing
when compared to that of a cat.
How to Read Skull Pathology
The pathology of a skull can tell you what may have caused an
animals death. Pathology is damage that may be the result of
trauma, disease or infection. These pathologic conditions might
tell you if the animal was hit buy a car, shot
by a gun, died from a disease or was killed by another animal.