Class Mammalia

Class MammaliaMammals

CharacteristicsFur or hair

Sweat glands

Mammary glands (females)Most important mammalian

characteristic

Diaphragm for breathing

Use various combinations of fur, hair and subcutaneous fat to conserve body heat

Three main categories1: Placentals

The young develop inside female uterus attached to a placenta = largest group

Three main categories2: Marsupials

Young are tiny an underdeveloped; they crawl to the female pouch, attach to a nipple an finish development there

Three main categories3: Monotremes

The young develop inside of eggs (similar to reptile eggs)

Most primitive group, 3 species left

(platypus and 2 kinds of echidna)

Adaptations for movementLand

Well developed muscles and boneSkeleton is also highly flexibleLimb structure permits ease of motion

and speedCat family: has grasping claws for

climbing and holding preySnowshoe hair: elongated hind limbs for

hopping in the snowGrazing animals have modified toes to

help with speed

FlightOnly bats

Have membrane between bones of wings

WaterWhales, dolphins and porpoises

Front limbs have become flippers

Tail propels through water

Streamlined body allows for speed

Blowhole instead of mouth

Otters and seals have similar adaptations but no blowhole

Digestive system:ruminants (cow, moose, deer,

camels)4 chambered stomach

First two chambers for bacterial fermentation

Food regurgitated for more mechanical breakdown before entering last two chambers

Last two chambers for chemical digestion

This is necessary because they live off of grass which is hard to fully digest