Download Skulls in Education

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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.
How to "read" a 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, giraffe and
cattle.
Some animals eat both plants and animals
(omnivores) and have both types of teeth.
Examples of omnivores include pigs, bears and
humans.
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How to "read" a skull: 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.
How to "read" a skull: 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 has
evolved 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 and judge 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 & Apes 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."
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How to "read" a skull: 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.
How to "read" a 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.
How to Identify a Skull:
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.
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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.
Bobcat Skull
Raccoon Skull
www.skullsunlimited.com/graphics
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Beaver Skull