Facts About Old World Monkeys You Gotta Read

Fact about mandrills
Opposable thumbs? Check. Largest monkey in the world? Check. Surviving in snow-clad regions? Check. As you go through facts about Old World monkeys provided by Buzzle, you will realize that there is a lot more to these species beyond the fact that they are found in Africa and Asia, i.e., the Old World.
Are there Monkeys in Europe?
The population of Barbary macaques (Macaca sylvanus) in Gibraltar, the southern tip of Spain, is known to be the only wild population in Europe.
Old World monkeys are species belonging to the Cercopithecoidea superfamily of primates. The group has over 130 species to its credit. While most of these are arboreal (i.e., tree-dwelling), terrestrial species also exist. As far as their characteristics are concerned, Old World monkeys are typically characterized by their downward-pointing nostrils, opposable thumbs, long rostrum, and furless palms and soles. Additionally, in most species, the forelimbs are shorter than the hind limbs.

Old World monkeys are medium to large in size, but larger than those found in the New World, i.e., the Americas. All Old World species do have a tail, but then, it is non-grasping or not prehensile like that of New World monkeys, so they can't use it to lift objects. It is their features, such as the shape of their nose, opposable thumbs, non-grasping tail, etc., that distinguish Old World from New World monkeys.
Range and Habitat
Old World Monkeys Range
Geographic Range of Old World Monkeys
As their name suggests, Old World monkeys are native to the Old World, i.e., Africa, Asia, and Europe. Though they are only found in Africa and Asia as of today, fossil evidence suggests that species belonging to this group also thrived in Europe in the past.

These monkeys are found in a range of habitats, including tropical rainforests of Southeast Asia, African Savanna, as well as dry shrublands and even mountainous terrain with heavy snowfall. Furthermore, some of these species are even found in urban areas in the vicinity of humans.
Classification
Old World monkeys are classified into two subfamilies: (i) Cercopithecinae subfamily; and (ii) Colobinae subfamily.
Cercopithecinae
Patas Monkey Erythrocebus Patas Sitting on Rock
Patas monkey
The species belonging to the Cercopithecinae subfamily are identified by ischial callosities, i.e., a thickened piece of skin found on their buttocks and cheek pouches where they store food. Also, the species belonging to this subfamily are largely omnivores. Their diet includes leaves, fruits, insects, fish, and even meat. Baboons, for instance, are known to hunt other monkeys as well as young ones of other mammals.
Mandrill
Mandrill
The Cercopithecinae subfamily comprises species like baboons (genus Papio), mangabeys (genus Lophocebus, Cercocebus, and recently discovered Rungwecebus), mandrills (genus Mandrillus), patas monkey (lone species in genus Erythrocebus), macaques (genus Macaca), guenons (genus Cercopithecus), talapoins (genus Miopithecus), etc.
Colobinae
Snub-nosed monkey
Snub-nosed monkey
The species belonging to the Colobinae subfamily are characterized by their sacculated stomachs and absence of cheek pouches. They are predominantly herbivores, with low-protein, fibrous leaves making a chunk of their diet. The bacteria and enzymes present in the sack-like compartments of their sacculated stomach help them to break down plant cellulose more effectively, and thus, provide them more usable calories.
Gray langurs
Gray langurs
Colobinae subfamily comprises langurs or leaf monkeys (Genus Trachypithecus, Presbytis, and Semnopithecus), colobus monkeys (genus Colobus), proboscis monkey (lone species in genus Nasalis), snub-nosed monkeys (genus Rhinopithecus), etc.
Interesting Facts
✦ Talapoins, native to central Africa, are the smallest Old World monkeys, measuring 12 to 17 inches in length and weighing roughly about 3 lb.

✦ In contrast, mandrills are the world's largest monkeys, measuring 30 to 37 inches, excluding their 2- to 4-inch tail, and weighing about 110 lb.
Japanese Macaque
Japanese macaque
✦ Macaques boast of being the most widespread species, with their geographic range stretching from the grasslands of Africa to snow-clad mountains of Japan.

✦ The black-and-white colobuses native to Africa are the only Old World monkeys who do not have a thumb.

✦ The patas monkey (Erythrocebus patas) found in Africa is the fastest-running primate in the world, with the ability of clocking a speed of up to 34 mph.
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Proboscis Monkey
Proboscis monkey
✦ The proboscis monkey (Nasalis larvatus), endemic to the island of Borneo in Southeast Asia, can be easily identified by its unusually large nose, which grows as the animal ages.

✦ Most species of Old World monkeys, including langurs and mangabeys, are polygamous. The Mentawai langur (Presbytis potenziani) is the only exclusively monogamous species in the leaf-monkey group.
✦ In 2006, researchers unearthed two teeth belonging to early Colobine monkeys that are 12.5 million years old―the earliest Old World monkey fossil ever known―at the Tugen Hills in western Kenya.
Barbary Macaque at Rock of Gibraltar
Barbary macaque at the rock of Gibraltar
✦ The Barbary macaques that inhabit Gibraltar today are of North African origin. Their existence in this part of Europe can be attributed to the Moors' invasion of the Iberian Peninsula in 711.

✦ The Myanmar snub-nosed monkey (Rhinopithecus strykeri), which was discovered in northern Burma (Myanmar) in 2010, is the most recently discovered member of the Old World group.
Conservation Status
As with other primates, even Old World monkeys are threatened by loss of habitat and habitat fragmentation resulting from human activities. As a result, at least ten species, including the Dryas monkey (Cercopithecus dryas), Delacour's langur (Trachypithecus delacouri), and Celebes crested macaque (Macaca nigra), have been enlisted as critically endangered species by the International Union for Conservation of Nature (IUCN), while several others are categorized as endangered.

Old World monkeys are more closely related to anthropoid apes, like gorilla and chimpanzees, which isn't surprising, as both are Old World Catarrhines. However, there do exist differences between these two groups. While Old World monkeys have a tail, apes don't. Also, apes are predominantly ground-dwelling and generally, larger of the two.