Early cercopithecid monkeys from the Tugen Hills, Kenya

Area of Science:

• Paleontology
• Primate Evolution
• African Mammalian Paleofauna

Background:

• The evolutionary history of Old World Monkeys (Superfamily Cercopithecoidea) is not fully understood due to limited fossil evidence in Africa during the late Miocene (15-6 Ma).
• Understanding the early diversification of cercopithecids is crucial for reconstructing primate evolutionary pathways.

Purpose of the Study:

• To document the presence and antiquity of cercopithecids in the Tugen Hills, Kenya.
• To provide new fossil evidence that extends the known timeline of crown Cercopithecidae.
• To infer dietary adaptations of early colobine monkeys based on morphological analysis.

Main Methods:

• Paleontological excavation and analysis of fossil specimens.
• Radiometric dating of fossil-bearing strata.
• Comparative morphological analysis of fossil primate teeth and bones.

Main Results:

• Discovery of cercopithecid fossils dating to 12.5 Ma in the Tugen Hills, Kenya.
• This finding extends the known antiquity of crown Cercopithecidae by approximately 3 million years.
• The fossils represent one or two species of early colobines, exhibiting morphological traits suggesting a less folivorous diet compared to extant colobines.

Conclusions:

• The early Miocene fossil record of cercopithecids in Africa is more robust than previously thought.
• These findings provide critical insights into the early diversification and ecological roles of colobine monkeys.
• This research contributes significantly to our understanding of primate evolution in Africa during the Miocene epoch.