Major Groups:
* Monotremes: These are the most primitive mammals, laying eggs instead of giving birth to live young. Examples include echidnas and platypuses.
* Marsupials: These mammals give birth to relatively undeveloped young, which then complete their development in a pouch. Examples include kangaroos, koalas, and opossums.
* Placentals: This is the largest and most diverse group of mammals. They give birth to live young that have developed in a placenta within the mother's uterus. Examples include humans, dogs, cats, whales, and elephants.
Some Examples of Animals in Class Mammalia:
* Primates: Humans, monkeys, apes, lemurs
* Carnivores: Dogs, cats, bears, wolves, foxes
* Rodents: Rats, mice, squirrels, beavers
* Cetaceans: Whales, dolphins, porpoises
* Artiodactyls: Cattle, pigs, deer, giraffes
* Perissodactyls: Horses, zebras, rhinoceroses
* Proboscideans: Elephants
* Bats: All species of bats
* Insectivores: Hedgehogs, moles, shrews
* Lagomorphs: Rabbits, hares, pikas
* Pangolins: Scaly anteaters
* Sirenians: Manatees, dugongs
* Edentates: Sloths, armadillos, anteaters
This is just a small sampling of the incredible diversity within the class Mammalia. There are thousands of species, each with its own unique adaptations and characteristics.