Mammals make up a diverse group that includes rabbits, humans and whales. Because of this, scientists have classified mammals into 16 different orders with certain characteristics that define each of them.
Monotremata
Platypuses and Echidnas make up the most primitive mammals on Earth. In fact, these mammals still lay eggs like their reptilian ancestors. But platypuses still provide milk for their young. Amazingly, they do this without any nipples but secrete the milk from glands within their skin.
Proboscidea
Elephants belong to this mammalian order. Proboscideans have long trunks, tusks and loose skin. To tell the difference between the African and Asian elephant is through their ears. The African Elephant has large ears that resemble Africa. Asian elephants have smaller ears.
Sirenia
Manatees and Dugongs belong to this order. Sirenians are aquatic organisms with no hind limbs. In fact, manatees have rounded tails, while the dugong has a split tail like dolphins. Sirenians are also herbivores.
Xenarthra
Anteaters and Armadillos belong to the Xenarthra order. They are known for having reduced or no teeth. But they can be both herbivores or carnivores. Usually, carnivores rely on insects as their food source.
Lagomorpha
The Lagomorpha order contains rabbits and hares. Their chisel-like incisors constantly grow, which may be a problem with pet rabbits, as their teeth will not stop growing. Lagomorphs are herbivores and are well adapted to jumping and running.
Carnivora
Carnivora contains dogs, cats, bears, seals, raccoons and otters. Their order is named after their main diet, which is carnivorous. Carnivoras have sharp canines and molars for shredding meat. Seals and dogs are closely related.
Artiodactyla
Pigs, cows, deer, and giraffes belong to this order. Artiodactylas consist of even-toed ungulates. The hooves of these animals are the toes of the animal. This is what makes them so much faster compared to other orders of mammals, such as the Carnivora.
Cetaceans
Whales and dolphins are the majority of this order. They are marine animals that are also carnivorous. Cetaceans have a thick layer of blubber that helps keep them warm in cold waters. Cetaceans are closely related to even-toed ungulates, with hippopotamus being their closest living relative that is still on land.
Marsupials
Kangaroos, opossums and koalas are all marsupials and is also another primitive group of mammals. However, they are not as primitive as the monotremata. Marsupials give birth to live babies, but the babies will spend the first part of their lives living in the mother’s pouch.
Tubulidentata
The only animal that still is alive today that belongs to this order is the aardvarks. Their teeth consist of many thin tube-like structures that are stuck together. The main diet for aardvarks is ants and termites.
Hyracoidea
Hyraxes belong to this order and resemble rodents. They are herbivores and have a complex multi chambered stomach, which allows them to digest the cellulose from their vegetarian diet.
Rodentia
The order Rodentia contains rats, mice, beavers and squirrels. This order is the most diverse order of all the mammals. Their front incisors also continuously grow but are worn down through constant gnawing. The Capybara is the largest rodent in the world.
Primates
Monkeys, gorillas and humans are all in the Primate order. They have opposable thumbs, highly developed brains, and forward facing eyes. Primates tend to be omnivorous, which means they eat both plant and animal matter.
Perissodactyla
Horses, rhinos and zebras belong to this order. Perissodactyls have hooves with an odd number of toes on each foot. But since they still run on their hooves, they run on their toes like the Artiodactylas.
Chiroptera
This order belongs to the bats, the only flying mammals in the world. Bats are usually nocturnal and have extremely poor eyesight, so they use sonar to locate their food. One reason bats are nocturnal is to stay safe from predators. Birds of prey are a constant threat to bats.
Eulipotyphla
This order belongs to mostly insectivores like moles and some shrews. They are known for spending most of their lives under ground and usually are blind.
