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