By Order:
* Primates: Monkeys, apes, humans, lemurs, and tarsiers. Known for their intelligence, grasping hands, and generally five-fingered hands and five-toed feet.
* Artiodactyla: Even-toed ungulates like cows, pigs, deer, sheep, goats, hippos, and giraffes. Their most distinctive feature is their even number of toes.
* Perissodactyla: Odd-toed ungulates like horses, rhinoceroses, and tapirs. They have an odd number of toes.
* Cetacea: Whales, dolphins, and porpoises. These marine mammals are adapted for aquatic life with streamlined bodies, flippers, and blowholes.
* Carnivora: Dogs, cats, bears, seals, sea lions, and weasels. These are generally meat-eating animals with sharp teeth and claws.
* Rodentia: Rats, mice, squirrels, beavers, and porcupines. The largest order of mammals, they have sharp incisors that grow continuously.
* Lagomorpha: Rabbits, hares, and pikas. They have two pairs of upper incisors, unlike rodents.
* Pholidota: Pangolins, the only mammals with scales. They are nocturnal, insectivorous animals.
* Proboscidea: Elephants. The largest land animals, characterized by their long trunks.
* Sirenia: Manatees and dugongs. They are herbivorous marine mammals adapted for aquatic life.
* Didelphimorphia: Opossums. These are marsupials, which means they have pouches where their young develop.
* Diprotodontia: Kangaroos, koalas, and wombats. They are marsupials with a pouch and two large lower incisors.
* Monotremata: Echidnas and platypuses. These are egg-laying mammals that also have pouches.
By Lifestyle:
* Marine mammals: Whales, dolphins, porpoises, seals, sea lions, walruses, manatees, and dugongs. They are adapted to live in the ocean.
* Terrestrial mammals: The majority of mammals live on land. They include a wide variety of species, from small rodents to large elephants.
* Flying mammals: Bats are the only mammals that can truly fly.
* Arboreal mammals: Some mammals live in trees, such as monkeys, squirrels, and sloths.
* Burrowing mammals: Other mammals live underground, such as moles, rabbits, and badgers.
By Diet:
* Herbivores: Mammals that eat plants, such as cows, horses, and rabbits.
* Carnivores: Mammals that eat meat, such as lions, tigers, and wolves.
* Omnivores: Mammals that eat both plants and animals, such as pigs, bears, and humans.
* Insectivores: Mammals that eat insects, such as shrews, moles, and bats.
This is just a small sample of the many types of mammals that exist. Each group has its own unique features and adaptations that allow them to thrive in their environment.