Page 52 - Mammal (DK Eyewitness)

Grippers and grinders Black bear skull

Mammals, being warm-blooded and generally
active, need to take in plenty of food to pro-
vide sufficient energy for life. The jaws and
teeth are at the forefront of feeding: they
grasp the food, cut it into smaller pieces if
necessary, and do some preliminary
crushing and grinding before it is
swallowed. The basic structure of the
mammalian tooth is a soft inside containing
nerve and blood vessels, overlaid by tough dentine, Canine tooth
and covered by enamel. Yet from this simple plan, Molar tooth
mammals have evolved a huge variety of choppers,
snippers, impalers, shearers, grippers, grinders, and THE ADAPTABLE BEAR
many other tooth shapes. Teeth are especial- Bears are classed in the
order Carnivora (p. 8), but
ly important in studies of mammal in reality some species eat
evolution, because they are often a variety of foods in season, Honeycomb
from fish, rodents, and
young deer to buds, fruits,
and berries - and the
well preserved as fossils and legendary honey. Fish flesh
so are one of the few ways of com- The bear’s teeth are
The male narwhal’s 10 ft paring extinct species with living adapted accordingly - pointed incisors and canines for the meat
(3 m) “tusk” is an overgrown and grinding molars for plant material.
left tooth. Its function is not ones (pp. 12-15).
certain - it may be a male
symbol to win over females. MOUTHFUL OF GRASS
The horse’s teeth are in two main
Very long groups. Small, sharp ones at the front
PANDA PUZZLE incisor teeth are (incisors and canines) work with the
The giant panda has long puzzled experts. Its general orange in color lips and act as croppers to snip off grass.
body structure indicates that it belongs to the order Carni- Large, flat teeth at the back (molars)
vora (meat-eaters), yet its diet is principally herbivor- grind the nutrients out of the grass.
ous - it eats mostly bamboo, although it will also eat
insects, small mammals, and carrion. Recent evidence Small canine tooth (“tush”),
suggests that its closest relatives are probably the bears. only in male horse

Panda lower jaw
Incisors
Large, flattened
tooth for chewing Canadian beaver
plants, typical of lower jaw
an herbivore
EVER-GROWING
INCISORS
The beaver is a Large
member of the order molar
Rodentia (p. 9). tooth
Rodents have long,
chisel-like incisors
(front teeth) specially
designed for gnawing.
These teeth are
contin-ually worn
down as they chip Grass
and chisel at wood
and other tough plant
food, so it is good
that they grow all the
time - otherwise the
Bamboo - beaver would starve.
the panda’s
main food
Large canine tooth Bark and buds - Horse
typical of carnivore the beaver’s food lower jaw

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