Major Groups (Orders):
* Primates: Monkeys, apes, lemurs, tarsiers.
* Rodents: Mice, rats, squirrels, beavers, porcupines.
* Artiodactyls: Even-toed ungulates (hooved animals), like cows, pigs, hippos, deer, giraffes.
* Perissodactyls: Odd-toed ungulates, like horses, zebras, rhinoceroses.
* Cetaceans: Whales, dolphins, porpoises.
* Carnivores: Cats, dogs, bears, seals, sea lions, weasels, badgers, hyenas.
* Bats: The only mammals capable of true flight.
* Marsupials: Possums, kangaroos, koalas, wombats (found mainly in Australia and the Americas).
* Monotremes: The most ancient group of mammals: echidnas and platypuses (found only in Australia and New Guinea). These lay eggs.
* Proboscideans: Elephants, the largest land mammals.
* Sirenians: Manatees and dugongs, aquatic herbivores.
Other Groups:
* Insectivores: Shrews, moles, hedgehogs.
* Lagomorphs: Rabbits, hares, pikas.
* Pangolins: Scaly anteaters (found in Africa and Asia).
* Aardvarks: Nocturnal, ant-eating mammals found in Africa.
Interesting Facts:
* Evolutionary Diversity: Mammals have evolved into an incredibly diverse group, adapted to almost every habitat on Earth.
* Endangered Species: Many mammal species are facing threats from habitat loss, poaching, and climate change.
* Adaptations: Mammals have unique adaptations, such as fur, mammary glands, and warm-bloodedness, that help them survive in diverse environments.
Let me know if you'd like to learn more about any specific group!