Mammal Classification
Primates
Primates are a diverse group linked by a number of important characteristics. They have well-developed brains protected by rounded brain cases, and large, forward-facing eyes that provide them with excellent visual abilities, particularly depth perception. Largely herbivorous, many primates are omnivorous when an opportunity arises. Most have powerful hind limbs and strong, gripping hands and feet (with flat nails instead of claws), suitable for their primarily arboreal lifestyle. Although some of our closer primate relatives, such as the chimpanzee, share at least partially our terrestrial lifestyle, only Homo sapiens is truly bipedal.
Primates are divided into two suborders: the Strepsirhini, which includes the five lemur families (including the aye-aye) endemic to Madagascar and lorises; and the Haplorhini, which is composed of tarsiers, tamarins, New and Old World monkeys, gibbons and great apes (such as chimpanzees, gorillas and humans).
Lemurs and their close kin have elongated snouts that produce a foxlike face. However, it is the presence of a "tooth comb" of lower incisors and canine teeth and a "toilet claw" for grooming on the second digit of the foot that unites them. The smallest of all primates are strepsirhine: The smallest dwarf lemur rarely weighs more than 1.5 ounces (40 g).
Haplorhine primates possess sparsely haired noses and share reproductive patterns. In contrast to the general mammalian pattern of seasonal breeding, most haplorhine females have year-round sexual cycles. To prepare for fertilization, their uterine wall develops a tissue, called endometrium, that is shed every month if no fertilization occurs. Only elephant-shrews also experience the copious blood loss (menstruation) that accompanies this shedding.
Next >>Carnivores
