Mammals

• 4,629 species• Phylum Chordata

"back-boned animals"

Four Distinct Features

Mammal Characteristics

• Subphylum Vertebrata

Vertebrates = true back-bone

- Vertebral column or backbone, generally replaces notocord

- Brain enclosed in cranial cavity (e.g., skull)

- Endoskeleton

Mammal Characteristics

• Class Mammalia – Subclass Prototheria

– Subclass Theria

Mammal Characteristics

• Class Mammalia

Distinguishing Features

Mammal Characteristics

*Exception to the Rule:

1) monotremes:

2) marsupials:

Mammals in Michigan

9 Orders of Mammals in MI– Didelphimorphia– Insectivora– Chiroptera– Primates– Carnivora– Perissodactyla– Artiodactyla– Lagomorpha– Rodentia

A. Monotremes (Order Montremata)

e.g, echidnas & duck-billed platypus

MAMMALIAN DIVERSITY: AN MAMMALIAN DIVERSITY: AN ORDERLY OVERVIEWORDERLY OVERVIEW

MAMMALIAN DIVERSITY: MAMMALIAN DIVERSITY: AN ORDERLY OVERVIEWAN ORDERLY OVERVIEW

B. Marsupials

1. South American Marsupials

a. Order Didelphimorphia

Wooly opossum Virginia opossum Mouse opossum

B. Marsupials

2. Australian Marsupials

a. Order Dasyuromorphia

MAMMALIAN DIVERSITY: MAMMALIAN DIVERSITY: AN ORDERLY OVERVIEWAN ORDERLY OVERVIEW

Tasmanian devil

B. Marsupials

2. Australian Marsupials

b. Order Peramelemorphia

MAMMALIAN DIVERSITY: MAMMALIAN DIVERSITY: AN ORDERLY OVERVIEWAN ORDERLY OVERVIEW

Rabbit-eared bandicoot

B. Marsupials

2. Australian Marsupials

c. Order Diprotodontia…

MAMMALIAN DIVERSITY: MAMMALIAN DIVERSITY: AN ORDERLY OVERVIEWAN ORDERLY OVERVIEW

Feather-tail gliderEastern gray kangaroo

KoalaKoala

Honey possum

C. Placental Mammals–Order Xenarthra (= Edentata)

(anteaters, sloths, armadillos)

Giant anteater Nine-banded armadilloNine-banded armadillo

C. Placental Mammals

– Order Insectivora

(shrews, moles, tenrecs)

Short-tailed shrewShort-tailed shrew Eastern mole

Streaked tenrec

C. Placental Mammals–Order Dermoptera

(colugos)

C. Placental Mammals–Order Chiroptera

(bats)

Mastiff batMastiff bat

C. Placental Mammals–Order Primates

(lemurs, monkeys, apes, humans)

Ring-tailed lem

ur

Orang-utan

Japanese macacques

C. Placental Mammals

–Order Carnivora

(dogs, cats, weasels, bears, hyenas, mongooses, civets, pinnipeds)

Gray wolf Cheetah

Grizzly bear

California sea lion

C. Placental Mammals–Order Cetacea

(whales, dolphins)• toothed whales (odontocetes)

Orca whale

C. Placental Mammals–Order Cetacea

(whales, dolphins)

• baleen whales (mysticetes)Blue whale

C. Placental Mammals–Order Proboscidea

(elephants)African elephant

C. Placental Mammals–Order Perissodactyla

Odd-toed ungulates(horses, rhinos, tapirs)

Asiatic tapir

–Order ArtiodactylaC. Placental Mammals

Even-toed ungulates(pigs, peccaries, hippos, camels, giraffes, deer, antelope, sheep, goats, cattle)

Dromedary camel Caribou

C. Placental Mammals–Order Lagomorpha

(rabbits, hares, pikas)Rocky Mountain pika

C. Placental Mammals–Order Rodentia

(squirrels, gophers, kangaroo rats, voles, porcupines, capybara)

N. pocket gopher

Prairie vole

Capybara

Mammal Characteristics – Soft Anatomy: Hair/Fur/Pelage

• key distinguishing feature

Dreiartgruppen:

Mammal Characteristics – Soft Anatomy : Hair/Fur/Pelage

Hair = body covering for:1) insulation;

2) coloration

Mammal Characteristics – Soft Anatomy : Hair/Fur/Pelage

2) Coloration

c) disruptive coloration -

d) warning coloration

• Pelage consists of stiff guard hairs and downy underfur

Mammal Characteristics – Soft Anatomy : Hair/Fur/Pelage

• vibrissae:

• - Majority of mammals (excluding humans) molt hair annually or bi-annually

• hair follicle:

• hair: nonliving; consists of dead epidermal cells; strengthened by keratin (a structural protein)

Figure 2-2

Mammal Characteristics – Soft Anatomy : Hair/Fur/Pelage

Structure of Hair

1) medulla: inner layer of cells;

2) cortex: middle layer of cells;

3) cuticular scales:

Figure 2-3

Mammal Characteristics – Soft Anatomy: Special Skin Glands

Mammary glands - milk production for young; key distinguishing feature – Consists of alveoli for

milk secretion – alveoli:

– Alveoli connect to milk ducts which open into nipples

Mammal Characteristics – Soft Anatomy: Special Skin Glands Endocrine Control:

– Mammary gland development linked to

– Milk production stimulated by secretions of prolactin & somatotropin (growth hormone)

– Nursing provides the stimulus to the pituitary to continue prolactin production & lactation

Mammal Characteristics – Soft Anatomy: Special Skin Glands • Endocrine Control:

– Nursing also stimulates the release of oxytocin,