Sexual dimorphism in early anthropoids

Area of Science:

• Paleoanthropology
• Primate Evolution
• Primate Social Behavior

Background:

• Sexual dimorphism in canine/premolar tooth and body size is linked to social organization in living primates.
• Monogamous primate species exhibit minimal sexual dimorphism, unlike polygynous species with pronounced dimorphism.

Observation:

• The study examined three Oligocene primate species from Egypt: Aegyptopithecus zeuxis, Propliopithecus chirobates, and Apidium phiomense.
• Evidence of sexual dimorphism in canine/premolar tooth size was found in these fossil species.

Findings:

• This research presents the earliest evidence of sexual dimorphism among higher primates.
• The findings indicate that these early fossil anthropoids likely lived in polygynous social structures (single-male harems or multi-male groups).

Implications:

• The study suggests that complex social behaviors in higher primates evolved earlier than previously thought.
• This provides insights into the social dynamics and evolutionary history of early catarrhine primates.