Old World monkeys

The Old World monkeys or Cercopithecidae are a group of primates, falling in the superfamily Catarrhini with the apes. From the point of view of superficial appearance, they are unlike apes in that most have tails (the family name means "tailed ape"), and unlike the New World monkeys in that their tails are not prehensile. Technically, the distinction of Catarrhines from Platyrhines depends on the structure of the nose, and the distinction of Old World monkeys from apes depends on dentition.

Several Old World monkeys have anatomical oddities. The colobus has a stub for a thumb; the proboscis monkey has an extraordinary nose; the penis of the male mandrill is colored red and the scrotum has a lilac color, while the face also has bright coloration like the genitalia and this develops in only the dominant male of a multi-male group.

The Old World monkeys are native to Africa and Asia. They include many of the most familiar species of non-human primates. The taxonomy of the Old World monkeys is disputed, and the following list of 21 genera is non-authoritative and has not been placed in an order that reflects modern cladistic research. Some authorities would recognise fewer genera than are listed here, and the numbers of distinct species in many genera is also in question. For this reason, the common names (many of which are in widespread use) do not always map directly onto the scientific classification.

Two subfamilies are recognised, the Cercopithecinae, which are mainly African but include the large genus of macaques which are mainly Asian, and the Colobinae, which includes most of the Asian genera but also the three genera of colobus monkeys, all of which are African.

• Cercopithecinae
  • Allenopithecus: one species, Allen's monkey A. nigroviridis; Africa
  • Cercocebus: mangabeys, four species; Africa
  • Cercopithecus: guenons, up to 26 species; Africa
  • Chlorocebus: one species, the vervet C. aethiops; East Africa
  • Erythrocebus: one species, the patas monkey E. patas; Africa
  • Lophocebus: mangabeys, two species; Africa
  • Macaca: (macaques), around 20 species; mostly Asia but extending to North Africa
  • Miopithecus: talapoins, one or two species, western equatorial Africa
  • Papio: baboons, 2-5 species recognised; Africa
  • Theropithecus: one species, the Gelada baboon T. gelada; East Africa
  • Mandrillus: mandrills, two species, western equatorial Africa
• Colobinae
  • Colobus (colobus monkeys), five species, Africa
  • Nasalis: odd-nosed monkeys, one species, the Proboscis monkey N. larvatus; Borneo
  • Piliocolobus: Red colobus monkeys, 1-6 species recognised; Africa
  • Presbytis: langurs or leaf monkeys, 8 species; Malaysia and Indonesia
  • Procolobus: one species, the Olive Colobus monkey P. verus, West Africa
  • Pygathrix: Douc langurs, one species (P. nemaeus) with three subspecies; South-east Asia
  • Rhinopithecus: snub-nosed langurs, four species; Asia
  • Semnopithecus: one species, the Hanuman langur S. entellus; Indian subcontinent
  • Simias: one species, the pig-tailed langur S. concolor; Mentawai Islands, Indonesia
  • Trachypithecus: langurs or leaf monkeys, about 10 species; Asia