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
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