Mammals

Chapter 28

Evolution of Mammals

Derived Characteristics of ALL mammalsEndotherms

Mammary glands

Skeletal

4 chambered

heartEnucleated RBC

Muscular

diaphragm

Characteristics of MOST mammals

1. Live birth2. Corpus

callosum

3. Placenta

Skin & Hair

Integument (outer boundary layer)

1. Color variation of skina.Sun protection

b. Dominance displays

2. Provides protection by derivatives such as hooves, claws, nails, horns and antlers.

3. Holds hair/fur: (evolved from scales)

4. Holds glandsa. Sweat

b. Sebaceous

c. Scent

Hair

Horns & Antlers

Glands

Skull Characteristics

1. Nasal size related to reliance on sense of smell.

3. Eyes in front vs. eyes on side.

2. Large ears

Food and Feeding

Food and Feeding

Migration

Migration

Flight and Echolocation

Flight and Echolocation

Locomotion1. Cursorial2. Ambulatory

3. Saltatorial

4. Oscillatoryamphibious aquatic marine 5. Volant 6. Gliding (could

be arboreal)

7. Arboreal

8. Fossorial

Territoriality

Reproductive Cycles

Estrous cycle

monestrous

polyestrous

Monotremes

Marsupials

Marsupials

Eutherians – Placental Mammals

Eutherians – Placental Mammals