Q. What are the major orders of placental mammals? What are a few representative species and distinguishing features of each of those orders?

The orders into which placental mammals are divided are the following:

Artiodactyls mammals with an even number of fingers in claws or paws like cows, sheep, and giraffes. Carnivorous predators with canine teeth like dogs, lions, tigers. Cetaceans aquatic animals without posterior limbs and similar to fishes, like dolphins and whales. Edentates creatures with absent or rare teeth like armadillos, sloths, anteaters. Lagomorphs, small-sized mammals having three pairs of continuously growing incisive teeth specialized in gnawing, like hares and rabbits. Perissodactyls also known as ungulates (hooved) big-sized animals with an odd number of fingers in each pawfor example horses and rhinos. Primates characterized by the big cranium and well-developed brain like humans and apes. Proboscideans are big-sized animals whose nose and superior lip form the trunk (snout) for example elephants. Chiropterans are flying nocturnal mammals (bats). Rodents are animals with two pairs of continuously growing incisive teeth, e.g., mice, rats, castors, squirrels. Sirenians are aquatic mammals of freshwater dprived of posterior limbs, like manatees and dugongs.