Old World Monkeys, New World Monkeys and Apes
Old World monkeys are native to Africa and Asia today, inhabiting a range of environments from tropical rain forest to savanna, shrubland and mountainous terrain, and are also known from Europe in the fossil record. However, a free-roaming group of monkeys still survives in Gibraltar to this day. Old World monkeys include many of the most familiar species of nonhuman primates, such as baboons and macaques.
Old World monkeys are unlike apes in that most have tails, and unlike the New World monkeys in that their tails are never prehensile.
Two subfamilies are recognized, the Cercopithecinae, which are mainly African, but include the diverse genus of macaques, which are Asian and North African, and the Colobinae, which includes most of the Asian genera, but also the African colobus monkeys.
New World monkeys are the five families of primates that are found in Central and South America and portions of Mexico.
New World monkeys are small to mid-sized primates, ranging from the pygmy marmoset (the world's smallest monkey), at 14 to 16 cm (5.5 to 6.3 in) and a weight of 120 to 190 grams (4.2 to 6.7 oz), to the southern muriqui, at 55 to 70 cm (22 to 28 in) and a weight of 12 to 15 kg (26 to 33 lb). New World monkeys differ slightly from Old World monkeys in several aspects. The most prominent phenotypic distinction is the nose, which is the feature used most commonly to distinguish between the two groups. The clade for the New World monkeys, Platyrrhini, means "flat nosed". The noses of New World monkeys are flatter than the narrow noses of the Old World monkeys, and have side-facing nostrils. New World monkeys are the only monkeys with prehensile tails—in comparison with the shorter, non-grasping tails of the anthropoids of the Old World.
New World monkeys families classification are:
Family Callitrichidae: marmosets and tamarins
Family Cebidae: capuchins and squirrel monkeys
Family Aotidae: night or owl monkeys (douroucoulis)
Family Pitheciidae: titis, sakis and uakaris
Family Atelidae: howler, spider, woolly spider and woolly monkeys
Apes (Hominoidea) are a branch of Old World tailless anthropoid catarrhine primates native to Africa and Southeast Asia and distinguished by a wide degree of freedom at the shoulder joint indicating the influence of brachiation. There are two main branches: the gibbons, or lesser apes; and the hominids or great apes.
Lesser apes (Hylobatidae) include four genera and sixteen species of gibbon, including the lar gibbon, and the siamang, all native to Asia. They are highly arboreal and bipedal on the ground. They have lighter bodies and smaller social groups than great apes.
The Hominidae include orangutans, gorillas, chimpanzees, bonobos and humans. Alternatively, the family are collectively described as the great apes. There are two extant species in the orangutan genus, two species in the gorilla genus, and a single extant species Homo sapiens in the human genus. Chimpanzees and bonobos are closely related to each other and they represent the two species in the genus Pan.
Members of the superfamily are called hominoids (not to be confused with the family of "hominids" - great apes, the subfamily of hominines, the tribe of "hominins" aka the human clade, or the subtribe of hominans).
Some or all hominoids are also called "apes". However, the term "ape" is used in several different senses. It has been used as a synonym for "monkey" or for any tailless primate with a humanlike appearance. Thus the Barbary macaque, a kind of monkey, is popularly called the "Barbary ape" to indicate its lack of a tail. Biologists have used the term "ape" to mean a member of the superfamily Hominoidea other than humans, or more recently to mean all members of the superfamily Hominoidea, so that "ape" becomes another word for "hominoid".
Except for gorillas and humans, hominoids are agile climbers of trees. Their diet is best described as frugivorous and folivorous, consisting mainly of fruit, nuts, seeds, including grass seeds, and in some cases other animals, either hunted or scavenged (or farmed solely in the case of humans), along with anything else available and easily digested. Meat is not consumed by every species.
Most non-human hominoids are rare or endangered. The chief threat to most of the endangered species is loss of tropical rainforest habitat, though some populations are further imperiled by hunting for bushmeat.