Post on 13-Dec-2015
MammalsMammals
Bio II HonorsBio II Honors
RuppRupp
Origin and EvolutionOrigin and Evolution
4400 species4400 species More than 20 ordersMore than 20 orders Found on every continent and every Found on every continent and every
oceanocean
EndothermyEndothermy
Body heat Body heat produced through produced through metabolismmetabolism
Nearly constant Nearly constant temperaturetemperature
Regulated through Regulated through metabolism and metabolism and surface area surface area
HairHair
Main function is to Main function is to insulate against insulate against body heat lossbody heat loss
May also act as May also act as camouflagecamouflage
Completely divided heartCompletely divided heart
Four chambered Four chambered heart with two heart with two separate ventriclesseparate ventricles
Deoxygenated Deoxygenated blood does not mix blood does not mix with oxygenated with oxygenated bloodblood
MilkMilk
Females onlyFemales only Mammary glands Mammary glands
are modified sweat are modified sweat glands that glands that produce the milkproduce the milk
Single jawboneSingle jawbone
Unlike other Unlike other animals there is animals there is only one lower only one lower jawbonejawbone
Important in Important in identifying identifying mammal remains mammal remains due to decay of due to decay of other other characteristicscharacteristics
Specialized teethSpecialized teeth
Front teeth for Front teeth for biting and cuttingbiting and cutting
Side and back Side and back teeth for grindingteeth for grinding
Mammalian AncestorsMammalian Ancestors
300 million years ago 300 million years ago there were two major there were two major groups of animalsgroups of animals– One group gave rise to One group gave rise to
dinosaurs, birds, and all dinosaurs, birds, and all living reptilesliving reptiles
– The other group, the The other group, the synapsids, gave rise to synapsids, gave rise to mammals and their mammals and their relativesrelatives
Opening behind the Opening behind the eye in their skulleye in their skull
DimetrodonDimetrodon
TherapsidsTherapsids
The group that The group that rose from the rose from the synapsids and synapsids and gave rise to gave rise to mammals mammals
Many transitional Many transitional formsforms
Very complete Very complete fossil recordfossil record
Single jawbone Single jawbone witnessedwitnessed
Limbs moved Limbs moved under the bodyunder the body
Specialized teeth Specialized teeth evolvedevolved
Some may have Some may have been endothermic been endothermic and had hairand had hair
LycaenopsLycaenops
First MammalsFirst Mammals
Appeared the same Appeared the same time as the time as the dinosaurs—Triassic dinosaurs—Triassic periodperiod
Very small fossil Very small fossil remainsremains
Large eye sockets Large eye sockets suggests nocturnal suggests nocturnal existenceexistence
First MammalsFirst Mammals
By the end of the By the end of the Jurassic, 5 orders Jurassic, 5 orders of mammals had of mammals had evolvedevolved
Midway through Midway through the Cretaceous, 3 the Cretaceous, 3 main groups had main groups had evolvedevolved
Three Main Groups of MammalsThree Main Groups of Mammals
Monotremes—the egg layersMonotremes—the egg layers Marsupials—live birth, but short Marsupials—live birth, but short
internal development—pouched internal development—pouched animalsanimals
Placentals—live birth, long internal Placentals—live birth, long internal development, young nourished development, young nourished through a placentathrough a placenta
Diversification of MammalsDiversification of Mammals
Dinosaurs died out 65 myaDinosaurs died out 65 mya New habitats and niches opened up New habitats and niches opened up
and allowed evolutionary and allowed evolutionary diversificationdiversification
Benefits of EndothermyBenefits of Endothermy Able to live in cold Able to live in cold
climatesclimates Energy is available to Energy is available to
perform tasks for long perform tasks for long periods of timeperiods of time
Organ systems are Organ systems are arranged differentlyarranged differently
Food intake is Food intake is increasedincreased
Insulation to heat loss Insulation to heat loss through hair and fat through hair and fat layerslayers
Respiratory SystemRespiratory System
Very efficient Very efficient systemsystem
Large lungs and Large lungs and many alveoli for many alveoli for gas exchangegas exchange
Diaphragm to aid Diaphragm to aid inhalationinhalation
Tooth TypesTooth Types Incisors to cutIncisors to cut Canines to grip and punctureCanines to grip and puncture Premolars to shred and grindPremolars to shred and grind Molars to grind and crushMolars to grind and crush Baleen in whalesBaleen in whales
Plant DigestionPlant Digestion
CelluloseCellulose Multi-chambered Multi-chambered
stomachstomach Rumen—contains Rumen—contains
microorganismsmicroorganisms Regurgitate and chew Regurgitate and chew
the partially digested the partially digested cudcud
Cecum—fermentation Cecum—fermentation chamberchamber
Nervous Systems and Sense Nervous Systems and Sense OrgansOrgans
Enlargement of cerebrum accounts Enlargement of cerebrum accounts for the large brains of mammalsfor the large brains of mammals– Evaluates inputEvaluates input– Controls movementControls movement– Initiates and regulates behaviorInitiates and regulates behavior
Five sensesFive senses Various heightened senses depend Various heightened senses depend
on environment, Ex. Bats and on environment, Ex. Bats and echolocationecholocation
Monotreme ReproductionMonotreme Reproduction
Lays one to two Lays one to two leathery eggs and leathery eggs and incubates themincubates them
Developing embryo Developing embryo is nourished by the is nourished by the yolkyolk
Marsupial ReproductionMarsupial Reproduction
Very short internal Very short internal developmentdevelopment
At the point when At the point when they can survive they can survive outside the outside the mother’s body they mother’s body they emerge and move emerge and move into the pouchinto the pouch
Placental Mammal ReproductionPlacental Mammal Reproduction
Most familiar type Most familiar type of mammal of mammal reproductionreproduction
Long developmentLong development Nourished through Nourished through
a placenta a placenta containing blood containing blood vessels of mother vessels of mother and offspringand offspring
Order MonotremataOrder Monotremata Egg-layersEgg-layers Three speciesThree species
– PlatypusPlatypus– Two types of anteater or echidnaTwo types of anteater or echidna
PlatypusPlatypus– Aquatic adaptations—webbed feet, flattened tail, Aquatic adaptations—webbed feet, flattened tail,
duckbill muzzleduckbill muzzle– Nippleless mammary glandsNippleless mammary glands
EchidnaEchidna– TerrestrialTerrestrial– Coat of protective spinesCoat of protective spines– Probing noseProbing nose
Order MarsupialiaOrder Marsupialia
About 280 speciesAbout 280 species Only one U.S. species—OpossumOnly one U.S. species—Opossum Inhabit Australia, New Guinea, Inhabit Australia, New Guinea,
AmericasAmericas As Pangea drifted apart the isolation As Pangea drifted apart the isolation
allowed for diversification and allowed for diversification and domination in certain regions of domination in certain regions of these organisms—many were these organisms—many were replaced by placental mammalsreplaced by placental mammals
Placental MammalsPlacental Mammals Order Order RodentiaRodentia Order Order EdentataEdentata Order Order LagomorphaLagomorpha Order Order InsectivoraInsectivora Order Order PrimatesPrimates Order Order ChiropteraChiroptera
Order Order CarnivoraCarnivora Order Order ArtiodactylaArtiodactyla Order Order PerissodactylaPerissodactyla Order Order CetaceaCetacea Order Order SireniaSirenia Order Order ProboscideaProboscidea
Order Order RodentiaRodentia
Largest order with about 1800 species, about Largest order with about 1800 species, about 40% of all placental mammals40% of all placental mammals
Not found on AntarcticaNot found on Antarctica Two pairs of incisorsTwo pairs of incisors High reproductive capacityHigh reproductive capacity
Order Order EdentataEdentata
About 30 living About 30 living speciesspecies
Anteaters, sloths, Anteaters, sloths, armadillosarmadillos
EdentataEdentata means means “toothless”, “toothless”, anteaters have no anteaters have no teeth, armadillos teeth, armadillos and sloths have and sloths have peg-like teeth with peg-like teeth with no enamelno enamel
Order Order LagomorphaLagomorpha
Roughly 70 species Roughly 70 species including rabbits, including rabbits, hares, and pikashares, and pikas
Double row of Double row of upper incisorsupper incisors
Order Order InsectivoraInsectivora
About 390 speciesAbout 390 species Shrews, hedgehogs, Shrews, hedgehogs,
molesmoles High metabolic rateHigh metabolic rate Found in North Found in North
America, Europe, Asia, America, Europe, Asia, and Africaand Africa
Pointed, probing nosesPointed, probing noses Arboreal, Arboreal,
subterranean, or subterranean, or terrestrial adaptationsterrestrial adaptations
Order Order PrimatesPrimates
235 species235 species Prosimians—lemurs, tarsiers, lorisesProsimians—lemurs, tarsiers, lorises Anthropoids—monkeys, apes, humansAnthropoids—monkeys, apes, humans OmnivorousOmnivorous Large brainsLarge brains Variation in size-from 10 grams to 400 lbs.Variation in size-from 10 grams to 400 lbs. Forward facing eyes, and grasping handsForward facing eyes, and grasping hands
ProsimiansProsimians
AnthropoidsAnthropoids
Order Order ChiropteraChiroptera
More than 900 More than 900 speciesspecies
BatsBats Wing is a modified Wing is a modified
hand with a hand with a membrane membrane stretched over itstretched over it
Order Order CarnivoraCarnivora 274 species274 species Dogs, cats, bears, Dogs, cats, bears,
raccoons, seals, raccoons, seals, hyenas, etc.hyenas, etc.
Meat eaters that Meat eaters that typically have long typically have long canines, strong jaws, canines, strong jaws, and clawed toesand clawed toes
Long limbs to aid in Long limbs to aid in runningrunning
Pinnipeds—aquatic Pinnipeds—aquatic such as seals, such as seals, walruseswalruses
Order Order ArtiodactylaArtiodactyla About 210 speciesAbout 210 species Also known as the Also known as the
ungulates or hoofed ungulates or hoofed mammals—have even mammals—have even number of toesnumber of toes
Deer, elk, sheep, goats, Deer, elk, sheep, goats, pigs, camelspigs, camels
Native to every continent Native to every continent except Australia and except Australia and AntarcticaAntarctica
Use speed as defense Use speed as defense Typically herbivoresTypically herbivores RumenRumen
Order Order PerissodactylaPerissodactyla 17 living species17 living species Ungulates with odd Ungulates with odd
number of toesnumber of toes Horses, zebras, Horses, zebras,
rhinoceroses, tapirsrhinoceroses, tapirs Most are native to Most are native to
Africa and AsiaAfrica and Asia Tapirs can be found in Tapirs can be found in
Central and South Central and South AmericaAmerica
Cecum instead of Cecum instead of rumenrumen
Order Order CetaceaCetacea
90 species of whales, dolphins, and porpoises90 species of whales, dolphins, and porpoises Forelimbs are flippers, hind limbs modified to flippersForelimbs are flippers, hind limbs modified to flippers Blowholes and blubberBlowholes and blubber Echolocation for navigationEcholocation for navigation Entirely aquatic, but evolved from land mammalsEntirely aquatic, but evolved from land mammals Toothed whales and baleen whalesToothed whales and baleen whales
Toothed versus BaleenToothed versus Baleen
Order Order SireniaSirenia
4 species4 species Manatees and Manatees and
dugongsdugongs Inhabit rivers, Inhabit rivers,
estuaries, and tropical estuaries, and tropical waterswaters
Flippers and no hind Flippers and no hind limbs like cetaceanslimbs like cetaceans
Closely related to Closely related to elephantselephants
Order Order ProboscideaProboscidea
3 species3 species Boneless, trunked Boneless, trunked
nose, or proboscisnose, or proboscis ElephantsElephants Modified incisors Modified incisors
called tuskscalled tusks Long gestationLong gestation Live to about 80Live to about 80