Catarrhini

Definition

Catarrhini refers to a suborder of primates that includes Old World monkeys, apes, and humans. This group is characterized by their downward-facing nostrils, which distinguish them from the platyrrhines, or New World monkeys, who have side-facing nostrils. Catarrhini plays a crucial role in understanding primate evolutionary history due to their distinct anatomical features and their divergence from other primate lineages.

5 Must Know Facts For Your Next Test

1. Catarrhini is divided into two main superfamilies: Cercopithecoidea (Old World monkeys) and Hominoidea (apes and humans).
2. The evolutionary split between catarrhines and platyrrhines occurred approximately 40 million years ago.
3. Catarrhines typically have a more complex dental formula compared to platyrrhines, with their molars adapted for different diets.
4. Members of the Catarrhini exhibit a range of social behaviors, from solitary living in some species to complex social structures in others, like chimpanzees and bonobos.
5. The evolutionary adaptations seen in catarrhines, such as larger brains relative to body size, have implications for their cognitive abilities and social interactions.

Review Questions

• How does the anatomical structure of catarrhines differ from that of platyrrhines, and what significance does this have for their classification?
  • Catarrhines have downward-facing nostrils while platyrrhines have side-facing nostrils, which is a key anatomical difference that helps classify these primates. This difference in nasal structure is not just superficial; it reflects broader evolutionary adaptations. For instance, the differing nostril orientations have implications for olfactory capabilities and feeding behaviors, marking a divergence that has influenced their ecological niches and social structures.
• Discuss the evolutionary significance of the split between catarrhines and platyrrhines in the context of primate development.
  • The evolutionary split between catarrhines and platyrrhines around 40 million years ago is significant because it marks the emergence of two distinct lineages with unique adaptations. This divergence allowed catarrhines to develop traits such as greater intelligence and complex social behaviors seen in apes and humans. The adaptive radiation following this split led to diverse evolutionary paths that reflect different environmental pressures and ecological niches within Africa and Asia for catarrhines.
• Evaluate the role of catarrhine evolutionary adaptations in shaping the cognitive abilities and social structures of modern primates.
  • The evolutionary adaptations seen in catarrhines, particularly regarding brain size relative to body size and social complexity, play a crucial role in shaping their cognitive abilities and social structures. For example, the larger brains of species like chimpanzees facilitate advanced problem-solving skills and intricate social interactions. These adaptations not only influence individual behaviors but also impact group dynamics and community organization within species, highlighting how evolutionary changes can lead to significant behavioral consequences in modern primates.

Related terms

Platyrrhini:

Platyrrhini is the suborder of primates that includes New World monkeys, characterized by their flat noses with side-facing nostrils.

Hominidae: Hominidae, commonly known as the great apes, is a family within the Catarrhini that includes orangutans, gorillas, chimpanzees, and humans.

Anthropoid: Anthropoids are higher primates that include both catarrhines and platyrrhines, characterized by larger brains and more complex social structures.