Placental mammals are advanced mammals whose young are born at a relatively advanced stage (more advanced than the young of other mammals, the monotremes and marsupials). Before birth, the young are nourished through a placenta. The placenta is a specialized embryonic organ that is attached the mother's uterus and delivers oxygen and nutrients to the young.

There are almost 4,000 known species of placental mammals. There are more rodents and bats than other types of placental mammals. Scientifically, placental mammals are called eutherians.

AARDVARK Aardvarks are large mammals that eat ants.

AFRICAN ELEPHANT The African Elephant is the largest land animal.

AFRICAN WILD CAT African Wild Cats are fierce, solitary cats that are fast hunters.

ANTEATER Anteaters are mammals with very long snouts from South and Central America.

ANTELOPE Antelopes have beautiful horns.

ARCTIC WOLF Arctic wolves are meat-eaters that live in Northern Canada.

ARMADILLO An armadillo is a small, burrowing, armored mammal.

BADGER The badger is a nocturnal mammal with a black-and-white striped face.

BALUCHITHERIUM Baluchitherium (aka Paraceratherium) was a large, extinct, hornless rhinoceros. It was one of the largest land mammals.

BAT A bat is a flying mammal.

BEAR A bear is a big, furry mammal.

BEAVER The beaver is a large rodent that builds dams and dens.

BELUGA WHALE The beluga is a small, white, toothed whale that lives mostly in cold, arctic waters.

BINTURONG A dark, furry mammal from southeast Asia.

BISON The Bison (also called the American Buffalo) is the heaviest land animal in North America.

BLACK BEAR The Black Bear is a big bear that can be black or brown colored.

BLUE WHALE The blue whale is the biggest animal that ever lived. This huge mammal eats tiny food that it sieves through baleen.

BOBCAT A fierce, short-tailed wild cat from North America.

BOWHEAD WHALE The bowhead whale is a large whale which eats tiny food that it sieves through baleen.

CAMEL Camels are large mammals that live in dry areas.

CARIBOU Caribou live in Arctic regions.

CAT Cats are animals and are great pets.

Cats Cats are fast-moving, carnivorous mammals.

CHEETAH The cheetah is the fastest land animal.

CHIMPANZEE Chimpanzees are very intelligent apes and are closely related to people.

CHINCHILLA Chinchillas are soft rodents that live high in the Andes Mountains of South America.

CHIPMUNK Chipmunks are rodents that live in North America and Asia.

COW The milk we drink comes from cows.

DEER Deer are a shy, fast-moving plant-eaters.

DINGO The dingo is a wild dog from Australia.

Dogs Dogs are meat-eating mammals.

DOLPHIN A dolphin is a marine mammal with a long nose and teeth. It is a carnivore.

DONKEY Donkeys are hoofed mammals adapted to desert life.

DROMEDARY The dromedary is the Arabian or one-humped camel.

ELEPHANT The elephant is a big, gray animal with a trunk.

ELK Elk have beautiful antlers.

EOHIPPUS Eohippus was a tiny horse that lived 50 million years ago.

FENNEC FOX The Fennec fox is a small, desert fox with very large ears; it lives in the Sahara and in northern Saudi Arabia.

FERRET Ferrets are a type of weasel.

FLYING SQUIRREL Flying squirrels glide from trees, using a loose flap of skin between their legs and arms.

FOX The fox is a meat-eating mammal with a long, bushy tail.

GAZELLE Gazelles live in herds in Africa.

GERBIL Gerbils are small rodents that some people keep as pets.

GIRAFFE The giraffe is the tallest land animal.

GNU The gnu is a fast-running, herding, grass-eater from eastern Africa. It is also known as the wildebeest.

GOAT Goats are sure-footed, hoofed mammals.

GORILLA Gorillas are from Africa and are in danger of extinction.

GRAY WHALE The gray whale is a baleen whale that eats tiny organisms from the mud on the bottom on the ocean.

GRIZZLY BEAR The Grizzly Bear is a large mammal with a muscular hump on its shoulders.

GROUNDHOG The groundhog is a rodent that is also called the woodchuck.

HAMSTER A hamster is a small rodent that some people keep as pets.

HEDGEHOG A hedgehog is a small mammal with a spiny coat.

HIPPOPOTAMUS The hippopotamus is a large mammal that stays in the water a lot.

HORSE Horses are very fast runners. Primitive horses were very small.

HOWLER MONKEY The loudest monkey!

HUMAN BEING A human being is a mammal.

HUMPBACK WHALE Humpbacks are very acrobatic whales that sing beautiful, complex songs.

HYENA A meat-eating mammal that hunts and scavenges prey.

HYRACOTHERIUM Hyracotherium/Eohippus was a tiny horse that lived 50 million years ago.

JAGUAR The jaguar is a large, spotted wild cat from South and Central America.

KANGAROO RAT The kangaroo rat is a small rodent from North America.

LEOPARD Leopards are widely-distributed, spotted wild cats.

LION A group of lions is called a pride.

LLAMA Llamas are domesticated animals that are related to camels.

LORIS Large-eyed primates from Southeast Asia.

LYNX A powerful wild cat from Europe, Eurasia, and North America.

MAMMOTH Mammoth were a large elephant-like animals that lived during the ice ages.

MANATEE Manatees are gentle, slow-swimming, aquatic mammals.

MANDRILL Mandrills are large, brightly-colored Old World monkeys.

MEERKAT Meerkats (also called suricates)are a type of cat that can stand upright..

MINK Minks are small, short-legged members of the weasel family that live in wet environments.

MOLE Moles are almost-blind, burrowing mammals.

MONGOOSE Mongooses are sleek, meat-eating mammals.

MONKEY Monkeys are furry mammals with long, strong tails.

MOOSE A moose is a large type of deer from the USA and Canada.

MOUSE Mice are cute, small rodents with long tails.

MUSKRAT Muskrats are rodents that often build dome-shaped houses.

NAKED MOLE-RAT Naked mole-rats are small, almost hairless rodents who live in underground colonies in Africa.

NARWHAL The narwhal is an Arctic whale; the male has one huge tooth.

NORTHERN FUR SEAL The Northern Fur Seal is a marine mammal that lives in the northern Pacific Ocean.

OCELOT Ocelots are wild cats from the Americas.

ORANGUTAN Orangutans are large, tree-dwelling apes.

ORCA Orcas are killer whales. An orca eats hundreds of pounds of fish (including sharks) and marine mammals every day.

OTTER An otter is a playful aquatic mammal.

PANDA Pandas are black and white bears from China.

PANGOLIN The pangolin is an insect-eating mammal that has protective scales on its body.

PIG Pigs oink!

POLAR BEAR Polar bears are large and live in the far north.

PORCUPINE Porcupines are mammals with protective, needle-like quills on their body.

RABBIT A rabbit is a small, hopping mammal with big ears.

RACCOON The raccoon is a mammal with mask-like markings on its face and a ringed tail.

RAT A rat is a rodent with a long tail and pink eyes.

RED WOLF Red wolves are endangered carnivores from the eastern USA.

REINDEER Reindeer live in the far north.

RHINOCEROS A rhinoceros is a huge animal from Africa that has one or two horn-like spikes on its head.

RING-TAILED LEMUR A large-eyed primate from Madagascar.

Rodents Rodents are relatively small, prolific mammals whose front two top teeth continually grow.

SEAL Seals live in the ocean but breathe air. They are marine mammals.

SEA OTTER Sea otters are marine mammals with very dense, waterproof fur.

SHEEP Sheep are farm animals that are raised for wool and meat.

SHREW Shrews are perhaps the tiniest mammals. They are quite ferocious.

SKUNK Skunks are black and white mammals that can produce a terrible odor.

SLOTH A sloth is a slow-moving mammal that lives hanging upside-down from trees.

SMILODON Smilodon was the largest saber-toothed cat. It was a meat eater that lived during the last ice age and is now extinct.

SNOW LEOPARD Snow Leopards are rare, pale leopards from the snowy central mountains of Asia.

SQUIRREL Squirrels are rodents.

TARSIER Tarsiers are small mammals with enormous eyes.

TIGER Tigers are large, fierce cats that have stripes.

VAMPIRE BAT The vampire bat is the only bat that eats blood.

WALRUS A walrus is a northern marine mammal with ivory tusks.

WARTHOG The warthog is a wild pig from Africa.

WEASEL Weasels are small, furry mammals with short legs.

WHALE Whales are large marine mammals. Whales breathe air.

WILDEBEEST The wildebeest is a fast-running, herding, grass-eater from eastern Africa. It is also known as the gnu.

WOODLAND CARIBOU A rare caribou from Canada that eats lichens.

WOLF The wolf is a meat-eating mammal.

WOODCHUCK The Woodchuck is a rodent that is also called the groundhog.

WOOLLY MAMMOTH The woolly mammoth is a large elephant-like animal that lived during the ice ages.

YAK Yaks are large, strong, plant-eating mammals.

ZEBRA Zebras have black and white stripes.