EXPLORE > ANIMAL SPECIES
Mammals are warm-blooded vertebrates. Their bodies are usually covered (at least partially) by fur or hair. Females give birth to live young and nurse them by secreting milk. Mammals are classified into twenty-one separate groups, only some of which are represented here.
Mammals are warm-blooded vertebrates. Their bodies are usually covered (at least partially) by fur or hair. Females give birth to live young and nurse them by secreting milk. Mammals are classified into twenty-one separate groups, only some of which are represented here.
BATS (Chiroptera):
Bats are the only mammals in the world capable of sustained flight. Their forelimbs are adapted as wings and they are actually more maneuverable in the air than even birds thanks partly to a sophisticated sonar system which allows them to fly in complete darkness. Although physically they look similar to mice and other rodents, they are from a different biological family. There are approximately 1,200 species of bats worldwide. They are divided into two suborders: fruit-eating megabats and echolocating microbats.
CARNIVORES (Carnivora):
Carnivores are a diverse group of mammals characterized by hunting and eating other animals. The Latin term "carnivora" translates to mean "to devour flesh." Typically, carnivores have claws and teeth which aid in catching and eating prey. They are often very social animals who may hunt cooperatively in packs. Some species, like cats and pinnipeds, may rely entirely on meat to survive. Others, such as bears, may subsist one a combination diet of meat and plants.
CETACEANS (Cetacea):
A cetacean is a class of aquatic animal which includes whales, dolphins and porpoises. There are approximately 90 known cetacean species alive today. All of these animals are carnivores and have fins. Most live in the ocean although some can be found in fresh water like rivers. The can vary greatly in size, with some species being just over 3 feet (1 meter) long and the largest being the blue whale, the largest animal to ever live on Earth.
EVEN-TOED HOOFED MAMMALS (Artiodactyla):
Also known as ungulates, these animals are identified by their hoofs where their body weight is carried mostly by the third and fourth toes. There are over 200 artiodactyl species alive today, including pigs, camels, deer, antelope, sheep, goats and cattle. The earliest examples of ungulates date back 53 million years. Originally they were much more numerous but the numbers and types of ungulates decreased dramatically following the last Ice Age. Many ungulates have been domesticated and are of important social or economic value to human beings.
HARES, RABBITS AND PIKAS (Lagomorpha):
Lagomorphs contain two different families of animals: Leporidae (which includes hares and rabbits) and Ochotonidae (which contains pikas). In all, there are over 80 different species of lagomorphs alive today. These animals are distantly related to rodents and can trace their history back to Earth's earliest mammals which survived the great extinction event that ended the reign of the dinosaurs. This is a widely distributed order of animals with examples found on every continent except Antarctica.
MARSUPIALS (Marsupialia):
Marsupials are unique among mammals in that females of the species carry their young in a pouch after a live birth. This pouch contains nipples for feeding milk to the young. Marsupials are only native to Australia and the Americas, with common examples being the kangaroo, koala, opossums and Tasmanian devils.
PINNIPEDS (Pinnipedia):
Pinnipeds are a group of semi-aquatic marine mammals found mostly in the colder waters of the Northern and Southern hemispheres. Pinnipeds have a heavy layer of fat (called blubber) which protects them against the cold. Except for the walrus, all pinnipeds are covered in fur. These animals are carnivores with streamlined bodies and four limbs which have evolved into flippers. Pinnipeds will often pull themselves onto land to rest, mate or give birth.
RODENTS (Rodentia):
The term rodent is derived from a from the Latin word rodere, which means "to gnaw." This is a reference to the single pair of continuously growing incisors (front teeth) which characterize these species. Most rodents are small in size with robust bodies, short legs and long tails. Rodents make up about 40% of all mammals and are highly distributed around the world, found on every continent except Antarctica. Common rodents include mice, rats, squirrels, beavers and porcupines.
SEACOWS (Sirenia):
Sea cows are an order of fully aquatic, herbivorous mammals which may look similar to pinnipeds. These species live in the warmer waters of swamps, rivers, estuaries, wetlands, and coastal areas where they feed mostly on sea grasses. Their bodies are large and awkward-looking and they generally move slower through the water than other marine mammals. The best known sea cows are the dugong and manatee.