Mammals Vertebrate 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)

Hair Made of the protein keratin Keratin also makes up: Nails Claws Hooves Horns Antlers Tusks Hair Follicle Skin Mites

How Deer Antlers Grow

Horns, Antlers, & Tusks Horns –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 teatsNo. of young per litter primitive opossums kangaroos41 Tenrec (max. 32) Mastomys (African rat) wolves (dogs)4-6 pigs many artiodactyls41 pangolins21 bats2 (4)1 (4) whales, horses, manatees21 elephants21 primates21

The Approximate Constituents of the Milk of Various Mammals in ml/mg per liter AnimalWaterFatsProteinsSugarsAshK2OK2ONaO 2 CaOMgP2O5P2O5 Human ? Horse Cow Goat Pig Dog Reindeer Harp Seal ? Blue Whale ?14.3??4.26?6.23

4 Chambered Heart Mouse 500 beats/ min Human 70 beats/min Elephant 28 beats/min

Heart Rates in Various Mammals SpeciesResting bpmActive bpm Great Whale7 Elephant28 Lion40 Human70120 Rabbit200 Mouse Shrew

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

Remingtonocetus

Protocetus

Dorudon

Doruson vs Odontecetus

Dorudon

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 SERTHRALAGLYASPGLUVALGLUASPTHRPROGLY ALAALA ASNASN ALAALA THRTHR ARGARG HIS Chimpanzee SERTHRALAGLYASPGLUVALGLUASPTHRPROGLY ALAALA ASNASN ALAALA THRTHR ARGARG HIS Primate Gorilla SERTHRALAGLYASPGLUVALGLUASPTHRPROGLY ALAALA ASNASN ALAALA THRTHR LY S HIS Baboon ASNTHR GLYASPGLUVALASP SERPROGLY ASNASN ASNASN ALAALA GL N LY S HIS Lemur ALATHRSERGLYGLULYSVALGLUASPSERPROGLYSERH IS ASNASN ALAALA GL N LY S LEU Dog SER GLY ASPGLUILUASP THRPROSERASNLY S ASNASN ALAALA ALAALA NonPrimate Chicken GLNTHRGLY ALAGLUILUALAASNSERPROTHR LY S ASNASN SERSER GL N ARGARG ALA Frog ASPSERGLY LYSHISVALTHRASNSERALAHISALALY S ASNASN ALAALA ARGARG ARG

RAT DISSECTION Scientific Name: Rattus norvegicus Common 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

Thoracic Cavity

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