Mike Clinton
Introduction: The Mysterious Absence of Cheek Flanges in Orangutan Skulls
Orangutans are one of the closest living relatives of humans, sharing 97% of our DNA. Their unique physical features, such as long arms and reddish-brown fur, have captivated scientists and the general public alike. However, one curious aspect of orangutan anatomy has puzzled researchers for decades – the lack of cheek flanges in their skulls.
Cheek flanges are bony protuberances that extend from the sides of the face in male primates. They serve as a visual and physical display of dominance and are particularly prominent in species such as gorillas and baboons. The absence of cheek flanges in orangutans, despite being present in other great apes, has led scientists to investigate the evolutionary and ecological factors that may have contributed to this unique feature.
A Brief Overview of Orangutans and Their Skull Anatomy
Orangutans are arboreal primates found in Indonesia and Malaysia, with two distinct species: the Bornean and Sumatran orangutans. They have a distinctive skull morphology, with a large braincase and a long, prognathous face. Their teeth are adapted for a frugivorous diet, with broad molars for grinding tough plant material.
Unlike other great apes, orangutans have a relatively flat face, lacking the prominent ridges and protuberances seen in gorillas and chimpanzees. This includes the absence of cheek flanges, which are present in male gorillas and other primates as a visual display of dominance and aggression. The function and evolutionary significance of the absence of cheek flanges in orangutans remains a topic of much debate and investigation.