Primates are a group of mammals that includes monkeys, prosimians and apes. There are an about 350 species of primates alive today. Here we explore 10 facts about primates and find out more about the characteristics that make them different from other mammal groups.
FACT: Primates are divided into 2 basic groups which include the wet-nosed primates and the dry-nosed primates.
The wet-nosed primates (Strepsirhini) are the more primitive of the two primate groups. Strepsirhini include about 85 species of lemurs, galagos, lorises and pottos. The wet-nosed primates are so named for their rhinarium, a moist surface surrounding their nostrils.
The dry-nosed primates include tarsiers, apes and monkeys. There are more than 250 species of dry-nosed primates. Dry-nosed primates are so named for their lack of a rhinarium. Humans belong to the dry-nosed primates.
FACT: The earliest known primates belonged to the genus Altiatlasius.
Some of the earliest known primates belonged to the genus Altiatlasius, a group of mammals that appeared about 60 million years ago during the Paleocene Epoch. These early primates were squirrel-like in both their size and appearance.
FACT: Colugos are the closest living relatives to primates.
Colugos are tree-dwelling mammals and are adept gliders. They are thought to be the closest living relative to the primates. The next closest relatives to primates and colugos are the treeshrews.
FACT: Most primates are higly social and form complex social units.
Most species of primates form social groups of some kind. Monkeys, for example, live in troops that include several females, their young and one or more adult males. Mandrills, drill and gelada baboons form sizeable troops consisting of hundreds of individuals. New World monkeys live in monogomaous pairs. Although most species of primates live in social groups, there are a few primates that lead solitary lives including orangutans, some lemurs and a few galagos.
FACT: Primates have dextrous hands and feet.
Primates exhibit a variety of hand and foot structures that make them good at grasping, grooming and gripping. Since many species of primates live in trees, such mobility of the hands and feet is needed.
One example of the specialized hands primates have is exhibited by the aye-aye, a species that has an elongated middle finger that enables it to pry grubs from the crevaces of tree bark. Another example is that of the tarsiers, a group characterized by their rounded finger pads which help to improve their grip of tree branches. Chimpanzees, a group of primates that live on the ground and to some extent in the trees, have highly mobile hands and feet enabling them to navigate a variety of surfaces.
FACT: Primates occur in Central and South America, Madagascar, Africa and Asia.
Most primates live in tropical rainforests and are therefore absent from most of the colder climates throughout the world. Lemurs live in Madagascar, an island in the Indian Ocean, off the coast of souther Africa. Galagos and pottos live in Africa, as do a variety of Old World monkeys and apes. Lorises live in Asia and New World monkeys live in Central and South America.
FACT: Primates are hard for scientists to clearly classify.
Primates have a number of characteristics that are easily to recognize as being prevalant among members of the group. These include a round skull, large brain relative to their body weight, a high forehead, eyes that face forward, dextrous hands and feet, and two mammary glands. But none of these characteristics are unique to only primates. For example, sirenians and elephants also have only two mammary glands. Carnivores have forward facing eyes, and some whales have high brain to body weight ratios.
FACT: Primate diet is varied but often depends on the size of the species.
In general, small primate species eat insects and large primate species eat leaves and fruit. Small primates can gain enough energy from a diet of insects to support their high metabolism. They cannot, however, extract enough energy from plants nor can they wait the long times needed to digest plant material that larger primates can. Larger primates simply cannot eat enough insects to support their dietary needs and instead feed on plants and consequently have a lower metabolic rate.
FACT: The largest living primate is the eastern lowland gorilla.
The eastern lowland gorilla (Gorilla beringei graueri), a subspecies of eastern gorilla, is the largest of all living primates. Male eastern lowland gorillas can reach weights of over 550 pounds. Eastern lowland gorillas inhabit the forests of eastern Democratic Republic of the Congo.
FACT: The smallest living primate is the Berthe’s mouse lemur.
Berthe's mouse lemur (Microcebus berthae) is the smallest of all mouse lemurs and as such is also the smallest of all living primates. Berthe’s mouse lemurs average just over 3.5 inches in length and weigh a mere 1.1 ounces. Berthe’s mouse lemurs live in the Kirindy Mitea National Park in Western Madagascar.