Mammals. MAMMALS Kingdom Animalia Phylum Chordata Subphylum Vertebrata Class Mammalia.
Class Mammalia
description
Transcript of Class Mammalia
Class MammaliaMammals
CharacteristicsFur or hairSweat glandsMammary glands (females)
Most important mammalian characteristic
Diaphragm for breathingUse 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
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 batsHave membrane between bones of
wings
WaterWhales, dolphins and porpoisesFront limbs have become flippersTail propels through waterStreamlined body allows for speed Blowhole instead of mouthOtters and seals have similar
adaptations but no blowhole
TeethIncisors: biting and tearingCanines: holding and piercingPremolars: chopping and grindingMolars: chopping and grindingHuman dental formula: 2123 (this means for every half of a jaw there are 2
incisors, 1 canine, 2 premolars and 3 molars)Dental plan varies depending on the feeding
habits
Digestive system:ruminants (cow, moose, deer,
camels)4 chambered stomachFirst two chambers for bacterial fermentationFood regurgitated for more mechanical
breakdown before entering last two chambersLast two chambers for chemical digestionThis is necessary because they live off of grass
which is hard to fully digest