Monkey

Monkeys are tree-dwelling (arboreal) simians. They are in the primate order. Monkeys are intelligent, social animals. Monkeys have a tail, even if it is a short one.
The word "monkey" is a common-language term. It includes two different groups of primates. The big difference is between Old World monkeys and New World monkeys. Some examples of monkeys are macaques, baboons, guenons and marmosets.
Old World monkeys: Cercopithecidae. Apes are the descendants of Old World monkeys.
New World Monkeys: Platyrrhini or Ceboidea (same thing in effect)
Both groups are in the infraorder Simiiformes. That infraorder also includes the great apes and humans.
The simians (monkeys) are a sister group to the tarsiers - the two members in the suborder Haplorhini diverged some 60 million years ago. New World monkeys and catarrhine monkeys appeared within the simians roughly 35 million years ago. Old World monkeys and apes emerged within the catarrhine monkeys about 25 million years ago.
Lifestyle
Some monkeys live almost entirely in trees. Others live partly on the ground. Monkeys are mainly vegetarian, with a strong preference for fruit. However, they may eat a wide range of other food, like insects. Monkeys can live in forests and savannahs, but not in deserts. Some can live in snowy mountains, but more live in rainforests. There are none in the rainforests of Australia and New Guinea. Apparently, they never reached either of those huge islands.
Some monkeys are small, about long and in weight. Other monkeys are much larger, about long and in weight. A group of monkeys is called a "troop" of monkeys or a "tribe" of monkeys.
The two groups of monkeys live in different places: the New World Monkeys in South America and the Old World Monkeys live mainly in Africa and Asia. New World Monkeys are often smaller than Old World Monkeys. Monkeys have long arms and legs to help them swing from trees. The monkeys often climb with the help of their tails. Some monkeys' tails can wrap tightly around branches, almost like a "fifth limb". This type of tail is 'prehensile'.
The smallest known monkey is the pygmy marmoset. It is between and in size (without the tail). It weighs about . It lives in the treetops of rainforests in Brazil, Colombia and Ecuador. The largest known monkey is the mandrill. It can grow to about in size. Adults weigh up to , and spend most of their time on the ground.
The word monkey might have come from a popular German story, "Roman de Renart" (Reynard the Fox). In there, the name of the son of Martin the Ape is Moneke.
In Africa, monkeys can be sold as "bushmeat" (meat of wild animals). Monkey brains are eaten in some parts of Africa, South Asia, and China.
References
Notes
Related pages
Primate
Simian
Other websites
"The impossible housing and handling conditions of monkeys in research laboratories", by Viktor Reinhardt, International Primate Protection League, August 2001
The problem with pet monkeys: reasons monkeys do not make good pets , an article by veterinarian Lianne McLeod on About.com
Helping hands: monkey helpers for the disabled, a U.S. national non-profit organization based in Boston Massachusetts that places specially trained capuchin monkeys with people who are paralyzed or who live with other severe mobility impairments.
Basic English 850 words
Monkeys