Class MammaliaClass Mammalia

Add to online Mammal lectureAdd to online Mammal lecture

Reference back to A&P notes beginning of Reference back to A&P notes beginning of semestersemester

Prototheria - MonotremesPrototheria - Monotremes

3 extant genera3 extant genera all live in the Australia-New Zealand region:all live in the Australia-New Zealand region:

Duck-billed platypus (Duck-billed platypus (Ornithorhynchus)Ornithorhynchus) Echidna (Echidna (TachyglossusTachyglossus)) Long-beaked echidna or spiny anteater (Long-beaked echidna or spiny anteater (ZaglossusZaglossus ) )

not considered ancestral to theriansnot considered ancestral to therians specialized surviving sidebranchspecialized surviving sidebranch

MonotremesMonotremes

lay leathery eggs (1 or 2) in underground nestslay leathery eggs (1 or 2) in underground nests cloaca cloaca toothless as adultstoothless as adults skeletal differences skeletal differences

have cervical ribshave cervical ribs "reptilian" pelvic girdle"reptilian" pelvic girdle lack a bony housing for the earlack a bony housing for the ear

MonotremesMonotremes

young born very altricalyoung born very altrical

Parental careParental care platypus - young get milk by sucking/licking the belly platypus - young get milk by sucking/licking the belly

hair hair echidna – ventral pouch for incubating and 2 suckling echidna – ventral pouch for incubating and 2 suckling

regions.regions.

Subclass TheriaSubclass Theria Infraclass Metatheria Infraclass Metatheria

Old system - Order MarsupialiaOld system - Order Marsupialia Current – several ordersCurrent – several orders

Subclass TheriaSubclass Theria Infraclass Metatheria Infraclass Metatheria

Numerous during Cretaceous (end of Mesozoic)Numerous during Cretaceous (end of Mesozoic) Southern land masses were unitedSouthern land masses were united

During Cenozoic During Cenozoic southern masses split, joined northernsouthern masses split, joined northern Couldn’t compete with placentals.Couldn’t compete with placentals.

Subclass TheriaSubclass Theria Infraclass Metatheria Infraclass Metatheria

young born tiny, very immature (altricial)young born tiny, very immature (altricial) gestation shortgestation short

time in marsupium > uterustime in marsupium > uterus

Subclass TheriaSubclass Theria Infraclass Metatheria Infraclass Metatheria

Skeletal differences from eutherians Skeletal differences from eutherians shape of nasal boneshape of nasal bone ancestral dental formulasancestral dental formulas presence of epipubic bones presence of epipubic bones

poor thermoregulatorspoor thermoregulators

Subclass TheriaSubclass Theria Infraclass Eutheria Infraclass Eutheria

Known from late CretaceousKnown from late Cretaceous 18 extant orders18 extant orders

Order Xenarthra (Edentata)Order Xenarthra (Edentata)

most primitivemost primitive sloths, anteaters and armadillos (protective armor)sloths, anteaters and armadillos (protective armor) Strong clawsStrong claws adults few to 0 teeth (molars lack enamel)adults few to 0 teeth (molars lack enamel)

Order PholidotaOrder Pholidota

pangolins or scaly anteaters; pangolins or scaly anteaters; 7 species7 species tropical Africa/Asiatropical Africa/Asia Scaly, epidermal layer Scaly, epidermal layer

curl up for protectioncurl up for protection

Order PholidotaOrder Pholidota

pangolins or scaly anteaters; pangolins or scaly anteaters; 7 species7 species tropical Africa/Asiatropical Africa/Asia Scaly, epidermal layer Scaly, epidermal layer

curl up for protectioncurl up for protection eats ants and termiteseats ants and termites Long tongue, strong digging feetLong tongue, strong digging feet lack teethlack teeth

““Edentata clade”Edentata clade”

Order Xenarthra (Edentata)Order Xenarthra (Edentata) Armadillo and anteaterArmadillo and anteater

Order Pholidota – spiny anteaterOrder Pholidota – spiny anteater

Similarities considered convergent Similarities considered convergent evolutionevolution

Stand alone groupsStand alone groups

InsectivoraInsectivora

CarnivoraCarnivora

PrimatesPrimates

hands that grasphands that grasp often opposable thumb (pollex) or big toe often opposable thumb (pollex) or big toe

(hallux):(hallux): well-developed sense of touch well-developed sense of touch Most have flat finger/toenailsMost have flat finger/toenails

PrimatesPrimates

Enlarged brainEnlarged brain Stereoscopic color-visionStereoscopic color-vision Many omnivorous Many omnivorous Most are socialMost are social

PrimatesPrimates 2 subdivisions2 subdivisions

PrimatesPrimates 2 subdivisions2 subdivisions prosimiansprosimians or lower primates or lower primates

mostly small, nocturnalmostly small, nocturnal Most rely on smell more than sight or soundMost rely on smell more than sight or sound LemursLemurs, , tarsierstarsiers …. ….

PrimatesPrimates The The AnthropoidsAnthropoids or higher primates or higher primates

Most larger, diurnal. Most larger, diurnal. ApesApes

no tailsno tails Larger brainLarger brain Larger bodyLarger body More uprightMore upright Fewer offspring, slower to matureFewer offspring, slower to mature Sight more than smellSight more than smell

Monkeys Monkeys nearly all have tailsnearly all have tails

PrimatesPrimates New World:New World: all monkeys. all monkeys.

Fairly small and exclusively tree dwelling. Fairly small and exclusively tree dwelling. Marmosets and tamarins, Marmosets and tamarins, squirrel, spider, woolly, and howler monkeys, squirrel, spider, woolly, and howler monkeys,

Old World:Old World: comprise monkeys, apes and comprise monkeys, apes and humans.humans. Bigger and spend more time on the ground. Bigger and spend more time on the ground. Macaques, Baboons, Mandrills and Drills, Geladas, Macaques, Baboons, Mandrills and Drills, Geladas,

Mangabeys, Guenons, Leaf-eating monkeys (Langurs, Mangabeys, Guenons, Leaf-eating monkeys (Langurs, leaf monkeys, colobus, proboscis) (Cercopithecidae)leaf monkeys, colobus, proboscis) (Cercopithecidae)

PrimatesPrimates apes: apes:

HominidaeHominidae: : gorillasgorillas chimpanzees and bonobos (aka pygmy chimps),chimpanzees and bonobos (aka pygmy chimps), HumansHumans

PongidaePongidae: orangutan : orangutan HylobatidaeHylobatidae: gibbons and siamang : gibbons and siamang

ChiropteraChiroptera

Bats – only flying mammalBats – only flying mammal Wings – membrane between fingersWings – membrane between fingers

Different from birds and pterosaursDifferent from birds and pterosaurs

ChiropteraChiroptera

Bats – only flying mammalBats – only flying mammal Wings – membrane between fingersWings – membrane between fingers

Different from birds and pterosaursDifferent from birds and pterosaurs

Nocturnal, often forest dwellerNocturnal, often forest dweller Eyesight poorEyesight poor Well-developed echolocationWell-developed echolocation

ChiropteraChiroptera

Bats – only flying mammalBats – only flying mammal Wings – membrane between fingersWings – membrane between fingers

Different from birds and pterosaursDifferent from birds and pterosaurs

Nocturnal, often forest dwellerNocturnal, often forest dweller Eyesight poorEyesight poor Well-developed echolocationWell-developed echolocation

Related to primates?Related to primates?

DermopteraDermoptera

flying lemurs or colugos (2 species)flying lemurs or colugos (2 species) Squirrel sizeSquirrel size

GlidersGliders Skin stretched from neck, Skin stretched from neck,

to forelimbs to backfeetto forelimbs to backfeet

Related to Chiroptera?Related to Chiroptera?

1 clade1 clade

PrimatesPrimates Dermoptera (flying lemur)Dermoptera (flying lemur) Tree shrews Tree shrews ChiropteraChiroptera

??

UngulataUngulata

Order ARTIODACTYLA (even-toed ungulates eg. pigs, deer & cattle) Order CETACEA (whales and dolphins)

Order PROBOSCIDEA (elephants) Order SIRENIA (sea-cows) Order HYRACOIDEA (hyraxes)

Order PERISSODACTYLA (odd-toed ungulates eg. horses, tapirs and rhinos)

Order TUBULIDENTATA (the aardvark)

““Cetartiodactyla “Cetartiodactyla “

Artiodactylids and cetaceans closely Artiodactylids and cetaceans closely related!related! Cetaceans evolved from artiodactylidsCetaceans evolved from artiodactylids

Cetartiodactyla Cetartiodactyla

Artiodactylids and cetaceans closely Artiodactylids and cetaceans closely related!related! Cetaceans evolved from artiodactylidsCetaceans evolved from artiodactylids Closely related to hippos, not pigsClosely related to hippos, not pigs Hippos grouped w/ pigsHippos grouped w/ pigs

ArtiodactylaArtiodactyla

2 or 4-toed2 or 4-toed line of symmetry passes between digits 3 line of symmetry passes between digits 3

& 4& 4 Ankle structure differs from other Ankle structure differs from other

ungulates (greater flexibility)ungulates (greater flexibility) pre-molars different from molarspre-molars different from molars

ArtiodactylaArtiodactyla

Suborder Suina: pigs, peccaries & hippopotami: most primitive, regrouped

Suborder Tylopoda: camels & llamas

Suborder Ruminantia: cattle, antelopes, deer and giraffes: advanced artiodactyls.

CetaceaCetacea Suborder Odontoceti (toothed Suborder Odontoceti (toothed

whales)whales) Dolphins, killer whales, sperm whaleDolphins, killer whales, sperm whale

Suborder Mysticeti (the baleen) Suborder Mysticeti (the baleen) whales. whales. Blue whale, right whales, humpbackBlue whale, right whales, humpback

Proboscidea Proboscidea elephants - 2 genera, 2 specieselephants - 2 genera, 2 species AsianAsian AfricanAfrican

Tusks normally larger, both males & females have

Large, communal, herbivoresLarge, communal, herbivores

Large, communal, herbivoresLarge, communal, herbivores

Eyes Eyes SmallSmall neck not very flexibleneck not very flexible

Smell Smell ImportantImportant touch with trunk, touch with trunk, move to Jacobson’s organ (roof of mouth)move to Jacobson’s organ (roof of mouth)

TeethTeeth Incisors = tuskIncisors = tusk Molars – replaced from rear Molars – replaced from rear

TeethTeeth Incisors = tuskIncisors = tusk Molars – replaced from rear Molars – replaced from rear

Hearing and earsHearing and ears Low frequency communicationLow frequency communication Ears – thermoregulationEars – thermoregulation

Trunk – very sensitive (tactile)Trunk – very sensitive (tactile) Respiration (snorkel for aquatic ancestor?)Respiration (snorkel for aquatic ancestor?) Hose for waterHose for water

Trunk – very sensitive (tactile)Trunk – very sensitive (tactile) Respiration (snorkel for aquatic ancestor?)Respiration (snorkel for aquatic ancestor?) Hose for waterHose for water Chemosensory & tactileChemosensory & tactile

Trunk – very sensitive (tactile)Trunk – very sensitive (tactile) Respiration (snorkel for aquatic ancestor?)Respiration (snorkel for aquatic ancestor?) Hose for waterHose for water Chemosensory & tactileChemosensory & tactile Picking up objectsPicking up objects Communication – caress, threat displays, …Communication – caress, threat displays, …

Closest relative? Closest relative?

Closest relative? Sirenia!Closest relative? Sirenia!

Sirenia Sirenia

sea cows, dugongs, manatees (2 genera, 5 species)sea cows, dugongs, manatees (2 genera, 5 species) Large, slow moving herbivoresLarge, slow moving herbivores Usually solitaryUsually solitary

HyracoideaHyracoidea

Hyraxes (3 genera, 11 species)Hyraxes (3 genera, 11 species) Africa Africa rabbit size, rodent-like animals rabbit size, rodent-like animals

HyracoideaHyracoidea

Hyraxes (3 genera, 11 species)Hyraxes (3 genera, 11 species) Africa Africa rabbit size, rodent-like animals rabbit size, rodent-like animals 4 toes in front, 3 in rear, hoof-like nails4 toes in front, 3 in rear, hoof-like nails Rubbery soles – grip rockRubbery soles – grip rock

HyracoideaHyracoidea

Hyraxes (3 genera, 11 species)Hyraxes (3 genera, 11 species) Africa Africa rabbit size, rodent-like animals rabbit size, rodent-like animals 4 toes in front, 3 in rear, hoof-like nails4 toes in front, 3 in rear, hoof-like nails Rubbery soles – grip rockRubbery soles – grip rock

Related to elephants and Related to elephants and sirenssirens

PerissodactylaPerissodactyla

line of symmetry down third digitline of symmetry down third digit a full set of incisorsa full set of incisors greatly molarized pre-molarsgreatly molarized pre-molars

PerissodactylaPerissodactyla

line of symmetry down third digitline of symmetry down third digit a full set of incisorsa full set of incisors greatly molarized pre-molarsgreatly molarized pre-molars

2 lineages – horses vs. tapirs & 2 lineages – horses vs. tapirs & rhinosrhinos

Replaced by artiodactylidsReplaced by artiodactylids

TubulidentataTubulidentata

Aardvarks – 1 speciesAardvarks – 1 species Nocturnal, solitary, burrowerNocturnal, solitary, burrower Poor eyesight, Poor eyesight, Hearing and smell developedHearing and smell developed Specialize in termitesSpecialize in termites

Long sticky tongueLong sticky tongue Strong claws and forelimbsStrong claws and forelimbs

diggingdigging