MammalsVertebrate Zoology

What does the typical mammal look like?

Small Brown Nocturnal ~4450 species

Characteristics Hair

Endothermic

4 chambered heart

Diaphragm (muscle to aid breathing)

Most nourished by a placenta

Mammary glands produce milk

Gestation - length of time within the uterus

Weaning - time at which young stop drinking milk

Characteristics Skin with sweat glands, oil glands, scent glands, & mammary

glands

3 middle ear ossicles (Bones); malleus, incus, & stapes derived from the jaw

Mouth with diphyodont teeth (deciduous replaced with permanent)

Lower jaw fused into one bone

Moveable eyelids

Fleshy pinnae

Non-nucleated, biconcave red blood corpuscles (RBC’S)

HairMade of the protein keratin

Keratin also makes up:Nails ClawsHoovesHornsAntlersTusks Hair Follicle

Skin Mites

How Deer Antlers Grow

Horns, Antlers, & TusksHorns –Found on antelope, giraffe, & rhino Do not branch Permanent structures

Antlers – Found on deer Branch Fall off Covered in velvet which sloughs off

Tusks -Found in ungulates w/o horns

Why did the Irish Elk go extinct?

Skin with glands

Hyena scent gland

Panda scent gland

Dik Dik Scent Gland

Llama Scent Glands

Lemur Scent Glands on Arms

Scent glands and spraying

Spraying patterns of two mice

Mammary glands

modified apocrine sweat glands

key mammalian feature

complex system of ducts

surface opening: nipple or teat

Table: Relationship between No. of teats and species-specific litter size 

Group No. of teats No. of young per litter

primitive opossums 19-25 12

kangaroos 4 1

Tenrec 10-12 12 (max. 32)

Mastomys (African rat) 12-20 8-19

wolves (dogs) 4-6 4-6

pigs 10-14 6-12

many artiodactyls 4 1

pangolins 2 1

bats 2 (4) 1 (4)

whales, horses, manatees

2 1

elephants 2 1

primates 2 1

The Approximate Constituents of the Milk of Various Mammals in ml/mg per liter

Animal Water Fats Protein

s Sugar

s Ash

Human 870 40 15 70 ?

Horse 900 22 20 60 3.6

Cow 880 34 33 44 7

Goat 862 48 48 46 8.5

Pig 840 50 37 50 6.3

Dog 770 93 97 31 9.1

Reindeer 677 171 109 28 15

Harp Seal 437.9 428.2 119.8 ? 9.14

Blue Whale 471.7 381.3 127.9 ? 14.3

4 Chambered Heart

   

                

                   

    Mouse

500 beats/min

 

  

              

  

                   

    Human70

beats/min

 

  

             

   

                   

    Elephant28

beats/min

Heart Rates in Various Mammals

Species Resting bpm Active bpm

Great Whale 7

Elephant 28

Lion 40

Human 70 120

Rabbit 200

Mouse 500-600

Shrew 800 1320

Diaphragm Muscle used to change air pressure inside the

body in order to move air Less pressure = air moves in More pressure = air moves out

3 Middle Ear Ossicles

Otic hair cells

Single fused mandible

Mandible Comparison

Beaver

Squirrel

Prairie Dog

Rabbit

Lion

Sea Lion

Wolverine

Skunk

Shrew

Smilodon

Black Bear

Killer Whale

Elephant

Rhino

Hippopotamus

White-tailed Deer

Cow

Pig

Horse

Giraffe

Gorilla

Orangutan

Ungulates – Hooved Mammals

Perissodactyla - horses, rhinos, tapirs - "odd toed"

Artiodactyla - pigs, peccaries, hippos, camels, deer, antelope, cattle, sheep, goats - "even toed"

Perissodactyla

pe·ris·so·dac·tyla (pai'ris-oh dak ti'lah): from Greek perissos, strange, of numbers odd; daktulos, a finger or toe

Artiodactyla

ar·ti·o·dac·ty·la (är'tee-oh dak ti'la): from Greek artios, complete, of numbers even; daktulos, a finger or toe

3 Subclasses within the class Mammalia:

Prototheria or Monotremes (3 species)

Metatheria or Marsupials (275 species)

Eutheria or placental mammals (3982 species)

Monotremes Most primitive mammals

Only 3 species: duck-billed platypus and two spiny anteaters, or echidnas

Oviparous; eggs with a leathery shell; mothers nourish their young with milk after young hatch

Lack nipples

Live only in Australia & New Guinea

The name monotreme means one-holed (i.e.cloaca)

Echidna & Duck-billed Platypus

Marsupials

Viviparous Immature young

are incubated in the pouch

Tasmanian wolf

Flying Squirrel

Tasmanian Devil

Marsupial Mouse

Koala (Aboriginal for no drink

…They sleep for 19 hrs/day)

Wombat

Kangaroo

Wallaby

Marsupial Pouch

Opossum

The only time you see an opossum…

Mammalian Orders Monotremata – Echidnas & platypus Marsupiala – Opossum, kangaroo, koala Insectivora – Shrew, mole, hedgehog Chiroptera - Bats Primates – Apes, lemur, monkey, human Rodentia – Beaver, squirrel, mice, mole,

gerbil Lagomorpha- rabbit Carnivora - Bear, dog, cat, skunk, weasel Pinnipedia –Seal, walrus, sea lion Cetacea – Whale, dolphin, porpoise

Mammalian Orders

Sirenia - Manatee Proboscidea - Elephant Perissodactyla – Rhino, horse

Artiodactyla – Deer, Giraffe, Hippopotamus,

Whale Evolution

Pakicetus & Coyote Skulls

Pakicetus…The First Whale 53.5 mya

Ambulocetus

Ambulocetus

Remingtonocetus

Protocetus

Dorudon

Doruson vs Odontecetus

Dorudon

Basilosaurus

Basilosaurus

Ring-tailed Lemur (Primate)

Primate Characteristics General primate anatomical features Hands: prehensile with opposable thumbs tactile pads and nails on fingers and toes adapted for precision grip facilitating feeding and locomotion in the trees mobile arms: posture frees arms and hands for grasping Eyes: binocular vision color vision development of visual organs is achieved at the expense of

olfactory organs Face: large eyes and brain and reduced snout area Large brains: especially in cerebral cortex

Behavioral Characteristics Long infant dependency periods

Reduced litter size—usually just one (allowing mobility with clinging young and more individual attention to young)

Complicated social organization

Excellent manual dexterity

Well developed sense of sight

Good hand-eye co-ordination

Figure 1: Selected amino acid positions in the Hemoglobin of some vertebrates.   

Human Being SER THR ALA GLY ASP GLU VAL GLU ASP THR PRO GLY

Chimpanzee SER THR ALA GLY ASP GLU VAL GLU ASP THR PRO GLY

Primate Gorilla SER THR ALA GLY ASP GLU VAL GLU ASP THR PRO GLY

Baboon ASN THR THR GLY ASP GLU VAL ASP ASP SER PRO GLY

Lemur ALA THR SER GLY GLU LYS VAL GLU ASP SER PRO GLY

Dog SER SER GLY GLY ASP GLU ILU ASP ASP THR PRO SER

NonPrimate Chicken GLN THR GLY GLY ALA GLU ILU ALA ASN SER PRO THR

Frog ASP SER GLY GLY LYS HIS VAL THR ASN SER ALA HIS

RAT DISSECTION

Scientific Name: Rattus norvegicusCommon Name: Rat

Rat Dissection

External Anatomy

• Wash your rat

•Examine rat and take notice of the following: ears, whiskers, eyes, nostrils, anus, and nipples (only female)

External Anatomy

• Wash your rat

• Examine rat and take notice of the following: ears, whiskers, eyes, nostrils, anus, and nipples (only female)

Internal Anatomy

• Make sure that the rat is pinned down down on its back before you begin cutting ‘Skin’ the rat by separating the skin and muscle layers across the midsection

Internal Anatomy

• Cut through the muscle, careful not to cut too deep, and expose the inner organs. You should be able to find the liver, stomach, small intestine, large intestine, cecum, spleen and pancreas

Abdominal Cavity

Abdominal Cavity

Thoracic Cavity

Thoracic Cavity

A = left ovary (embedded in fat)B = upper oviduct (where fertilization takes place)C = uterus (richly supplied with blood vessels)D = vaginaE = fat (fat deposited around internal organs)F = liver (dark red; in several lobes)G = caecum (the first part of the large intestine; H = colon