Mammals Hickman Chapter 28 E-6

Mammals 4800 living species Characteristics Hair Placental Specialized teeth and jaws Advanced nervous system

Integument Epidermis Dermis Thicker Hypodermis

Hair Flexible strand of dead, keratinized cells Functions Main regions Root Shaft Hair bulb Arrector pili Types Underhair Guard hair

Horns and Antlers True horns Antlers Family Bovidae Hollow sheaths of keratinized epidermis Not shed, not branched Continuous growth Antlers Family Cervidae Solid bone Shed after breeding season

Glands Derived from the epidermis Sweat glands Sebaceous glands Eccrine Apocrine Sebaceous glands Scent glands Mammary glands

Sweat Glands Widely distributed on body Sweat Types Mostly water Eccrine (merocrine) Apocrine

Sebaceous Glands Occur over entire body Secrete sebum Associated with hair follicle Sebum functions

Teeth Many vertebrates have toothlike structures Mammalian teeth unique Three main parts Crown Neck Root Three main layers Enamel Dentin Pulp

Teeth Four types of teeth Shape of teeth reflects the type of diet Incisors Canines Premolars Molars Shape of teeth reflects the type of diet

Insectivores Most small Insects, small invertebrates Short intestine

Herbivores Two types Cellulose in diet Browsers/ grazers Gnawers No cellulases Anaerobic fermentation chambers Cecum

Carnivores Feed on herbivores Protein diet Easily digestible Short intestine

Omnivores Plant and animal tissues Food supplies vary by season May store food

Specimens Bison Coyote Black bear Bobcat Red fox Pronghorn Beaver Brown bear American weasel Mink Musk rat White-tailed deer Ground hog Wild boar Red squirrel Grey squirrel Jack rabbit Opossum Irmine Eastern cottontail