How are all the types of monkeys different from other primates, which include great apes like gorillas, orangutans, and chimpanzees—and us? One of the simplest ways to define a monkey when compared to other primates is to look to their tail. Monkeys also tend to have relatively flat and short faces, move with all four limbs, have hands and feet typically with a big toe or thumb, and live in social family groups. Apes have more upright posture and fully mobile shoulder joints. Monkeys also differ from nocturnal prosimians by having traits like fully enclosed bony eye sockets that help them see better during the day.
So now that we know what a monkey is, exactly how many types of monkeys are there? “Monkeys are broadly divided into Old World species—160 species, and New World species—174 species,” says Jessica A. Mayhew, PhD, assistant professor of anthropology and museum studies, and director of the Primate Behavior and Ecology Program at Central Washington University. So that’s 334 species altogether! Alm says Old and New World monkeys have different kinds of noses, with Old World monkeys having narrow noses with downward-facing nostrils. Dr. Rodrigues says their teeth and vision differ, with Old World monkeys having fewer teeth and color vision.
As their name suggests, Old and New World monkeys live in different geographic regions, with Old World monkeys in Africa and Asia, and New World in Central and South America. Dr. Rodrigues points out that many monkey experts are replacing the terms “Old World” and “New World” with African/Asian and Central/South American to reflect a less Euro-centric and co.l.o.ni.alist point of view.
- New World monkeys
Another major difference with the Central/South American monkeys is that some species of these types of monkeys have “prehensile” tails, which means they can grasp objects. “This means they can fully support their own body weight by h.an.ging from their tails,” Michelle Rodrigues, PhD, a biological anthropologist at the Beckman Institute at the University of Illinois says. These monkeys also spend a lot more time in trees, whereas African/Asian monkeys prefer the ground. New World monkeys have broad noses with outward-facing nostrils, Victor Alm, zoological manager, primate unit, Saint Louis Zoo, says. In addition, “some Central/South American monkeys vary in whether they have full-color vision, limited color vision—the equivalent of color-b.l.in.dness in humans—or a mix of the two, with all males color-b.l.in.d, but female varying,” Dr. Rodrigues says. New World monkeys can also be found in the Caribbean, including on this gorgeous Caribbean island you’ve never heard of.
Emperor tamarin, a New World monkey found in the Amazon basin.
Cebidae, Found in Central and South America.
Pitheciidae, mostly found in Brazil
- Old World monkeys
Old World monkeys are a group of primates native to Old World regions of the world, which include Africa, Southeast Asia, and India. Several characteristics distinguish Old World monkeys from New World monkeys. Old World monkeys are relatively larger compared to New World monkeys. They have opposable thumbs (similar to apes) and have nails on all toes and fingers. They also have nostrils that point down and are closer together (more like humans), while the New World monkeys have nostrils that point to the side. There are about 133 species of Old World monkeys classified into two subgroups; the Colobinae and the Cercopithecinae. The Colobinae consists of Asian species (and a few African species) such as red colobuses, snub-nosed monkeys, langurs, and lutungs. On the other hand, the Cercopithecidae consists of African species such as baboons, macaques, mandrills, and mangabeys. Some of the Old World monkeys that are critically e.nd.anger.ed include Dryas monkey, Pagai Island macaque, Celebes crested macaque, Miss Waldron’s red colobus, Preuss’s red colobus, kipunji, and the Sarawak surili.
Old World monkeys and humans share a common ancestor. Scientists say the evolutionary split may have occurred between 20 and 30 million years ago.
The Pagai Island macaque, which is also known as the Bokkoi, is scientifically known as Macaca pagensis. The species is native to the Mentawai Islands to the west of Sumatra.
Sarawak Surili are native to the island of Borneo, where they can be found in the Malaysian states of Sabah, Brunei, and Sarawak, Kalimantan, Indonesia.
Kipunji is endemic to the highland forests of Tanzania