Old World Monkeys

Old World monkeys, scientifically known as members of the family Cercopithecidae, are a diverse group of primates that inhabit Africa and Asia. They belong to the larger clade known as Catarrhini, which also includes the apes and is distinct from the New World monkeys of the Americas. This clade diverged from a common ancestor with the New World monkeys around 45 to 55 million years ago, while Old World monkeys and apes share a more recent common ancestry, diverging approximately 25 to 30 million years ago.

Classification and Genera

The family Cercopithecidae is the largest primate family, comprising 24 genera and 138 recognized species. Some notable genera of Old World monkeys include:

• Baboons (Genus Papio)
• Macaques (Genus Macaca)
• Red Colobus (Genus Piliocolobus)
• Mandrills (Genus Mandrillus)
• Proboscis Monkeys (Genus Nasalis)
• Vervet Monkeys (Genus Chlorocebus)

Common Names and Subfamilies

Old World monkeys are often referred to by common names such as talapoin, guenon, colobus, douc (also known as douc langurs), gelada, mangabey, langur, drill, surili, and patas. They are classified into two main subfamilies:

1. Cercopithecinae: Includes terrestrial and arboreal species such as baboons, macaques, and vervet monkeys.
2. Colobinae: Encompasses primarily leaf-eating monkeys such as colobus monkeys and langurs.

Habitat and Distribution

Old World monkeys have adapted to a variety of habitats ranging from tropical rainforests to savannahs and mountainous regions. They are predominantly found in Africa and Asia, with some species, like the Barbary macaque, inhabiting parts of Europe, specifically on the Rock of Gibraltar.

Physical Characteristics

Old World monkeys are characterized by their narrow, downward-facing nostrils, a trait that distinguishes them from New World monkeys. They typically have non-prehensile tails and ischial callosities, which are toughened skin patches on their buttocks that facilitate prolonged sitting.

Evolutionary Significance

The evolutionary journey of Old World monkeys provides insight into the broader evolution of primates. Their close phylogenetic relationship with apes makes them a vital subject for understanding the development of traits such as increased brain size and social complexity, traits that are hallmarks of Homo sapiens and their relatives.

Behavioral Ecology

Old World monkeys exhibit a wide range of social structures, from the complex multi-level societies of mandrills to the more simplistic troop structures of vervet monkeys. They are generally diurnal, with activities centered around foraging, socializing, and grooming.

Related Topics

• Ape Evolution
• Primate Anatomy
• Savannah Ecosystems
• Tropical Rainforest Biodiversity

These links provide additional pathways for exploring the rich tapestry of life and evolution that includes Old World monkeys and their close relatives.