12 orders of placental mammals

*the 6 remaining orders contain just ONE PERCENT of the mammalian species

• Living in southern North America, Central America, & South America

• About 30 living species

• Means “strange joints”

• Many of these organisms do not have prominent teeth

• Anteaters completely lack teeth

• Sloths, on other hand, are herbivores that are continuously growing teeth that are adapted to grinding plants

Order Xenarthra

• http://www.youtube.com/watch?v=ndMKTnSRsKM

Order Lagomorpha

• Lagomorphs ~ about 70 species Rabbits, hares, pikas

• Native to many continents

• Differ from rodents = have double row of incisors, with 2 large front teeth backed by 2 smaller ones

• Teeth continue to grow throughout lifetime

• Adaptation to herbivorous diet

Pikas http://www.youtube.com/watch?v=cqtm9dkAu4o

Difference between newborn rabbit & hare

• Kittens –

• Leverets --

Order Rodentia

• Rodents = largest mammalian order… +1,800 species (40% of placental mammals)

• Squirrels, marmots, chipmunks, gophers, muskrat, mouse, rat, beavers, porcupines

• Every continent except Antarctica

• Produce many young each litter

• Teeth consist of a few molars and premolars & 2 pairs of incisors that continue to grow throughout life

• http://www.youtube.com/watch?v=vVrZb21KSfI misconceptions of rodents

http://www.youtube.com/watch?v=-mj36HTIJFY&feature=related

Order Primates

• 235 living species : lemurs, tarsiers, monkeys, apes, gibbons, humans

• Most are omnivores & have teeth suited for a varied diet

• Brains have a relatively large cortex = enables complex behavior

• Wide range of body sizes and adaptations to live in a variety of terrains

• Most have forward-facing eyes that enables depth perception

• All have grasping hands

• All but humans have grasping feet

• Some have grasping tail (for living in trees)

Tarsier • http://www.youtube.com/watch?v=XAaH2gSUdbo

Order Chiroptera

• Only mammals that TRULY fly

• 900 species = BATS

• Found worldwide except in polar environments

• Modified front limb with a membrane of skin that stretches between extremely long finger bones to the hind limb

• Wingspan can measure up to 1.5 meters

• Bat’s clawed thumb sticks out from top edge of wing (used for walking, climbing, grasping)

• Small eyes & large ears for ECHOLOCATION

• Most are nocturnal & feed on insects

• Some tropical bats are diurnal & feed on fruit & flower nectar

• They have large eyes & keen sense of smell

• Few species feed on meat or blood

Order Insectivora

• ~390 species … shrews, hedgehogs, moles

• Found in North America, Africa, & Europe

• Insectivores ~ animals that eat insects

**NOT all insectivores belong to this order = ANTEATERS

• Most have long, pointed noses that enable them to probe into soil for insects, worms, etc.

• Sharp teeth for grasping and piercing prey

http://www.youtube.com/watch?v=1rkTdcCFCto

• Moles are members of the mammal family • Moles live underground and burrow holes. • Some species are aquatic or semi-aquatic. • Moles have cylindrical bodies covered in fur with small

or covered eyes; the ears are generally not visible. • They eat small invertebrate animals living underground. • Moles can be found in North America, Europe and Asia.

Order Carnivora

• ~274 living species: dogs, cats, raccoons, bears, otters, seals, hyenas, sea lions, walruses, ETC

• Carnivores ~ eat meat

• Most are skilled hunters with strong senses of sight and smell

• Other adaptations: strong jaws, long canine teeth, clawed toes, long limbs

• Aquatic carnivores=pinnipeds– Efficient swimming, streamlined body

and 4 limbs adapted for flippers – Return to land to sleep & give birth

http://www.youtube.com/watch?v=6xh2YpA1JzE

• When it comes to hunting prey, spotted hyenas seem to know the secret: divide and conquer!

Canada allowed hunters to kill more than 300,000 baby seals this year—one of the largest quotas in history.

http://www.youtube.com/watch?v=78RgacB9UgA

Order Artiodactyla

• <Mammals with hoofs = ungulates >• Deer, cattle, giraffes, pigs, camels, moose

• 2 main groups characterized by their foot structure and presence of rumen or cecum

• Rumen=chamber of the stomach that contains microorganisms *Animals that chew cud have this

Cud– portion of food that returns from a ruminant’s stomach back to the mouth to be chewed and swallowed again

“regurgitated food”

• Cecum=large sac that branches from the small intestine*Animals that don’t chew cud have this

• Ungulates with an even # of toes are artiodactyls

• Most are herbivores & are adapted to grind plants

http://www.youtube.com/watch?v=AHNFWmAe5yg

growing up giraffe • http://www.youtube.com/watch?v=NETitFcUY

HE giraffe birth

Order Perissodactyla

• Ungulates (have hoof) with an odd # of toes are perissodactyls

• Horses, rhinos, zebras, tapirs

• Most are native to Asia & Africa

• Some species of tapirs live in Central and South America

*Have a cecum

http://www.youtube.com/watch?v=n2F2LjKLYF8

san diego zoo tapir

• http://www.youtube.com/watch?v=PFRrsX_HxD8 national geographic

• Cetaceans include about 90 species : whales, dolphins, porpoises

• Have fish-shaped bodies with forelimbs modified as flippers

• Lack hind limbs

• Have broad, flat tails that help propel them thru the water

• Totally aquatic but evolved from land-dwelling mammals

• Breathe thru modified nostrils called blowholes

• https://www.youtube.com/watch?v=TcToXk1HazQ killer whale gives birth

• https://www.youtube.com/watch?v=DWsN63PRCW8 killer whales vs sea lions

Order Sirenia~Manatees & dugongs~

• 4 species make up this order .. Called sirenians

• Large, torpedo-shaped herbivores • Live in tropical seas, estuaries, and

rivers

• Front limbs are flippers modified for swimming

• Lack hind limbs and have flattened tails for propulsion

• Only sirenian found in North America is the manatee

https://www.youtube.com/watch?v=YProaycNpHE

Order Proboscidea

• Have nose modified into a long, boneless trunk =proboscis

• Only living species of this order are the Asian and African elephant (largest living land mammal)

• Live in families w/several families living in a herd

• Feeds on plants for up to 18 hours a day;

300-600 lbs per day

• Trunk allows them to gather water or gather leaves from high branches

• Modified incisors, (TUSKS), efficently dig up roots and strip bark from branches ; can grow up to 10 ft & weigh 200 lbs

• Longest gestation of any land mammal, 22 months

• Female elephants can continue to give birth until the age of 70

• Elephants can live to be 80 years old

• Sleep max of 4 hrs per day

• Largest brain of any animal

• https://www.youtube.com/watch?v=OGm62uybQr8 endangered elephants

• https://www.youtube.com/watch?v=lg0Lgw96Hj8 baby elephant

• https://www.youtube.com/watch?v=59v3PmKp-5Y elephant and dog