A team from Wits University's Evolutionary¹ Studies Institute has discovered a fossil monkey specimen² representing the earliest baboon³ ever found. Dating back more than 2 million years ago (between 2.026-2.36 million years ago), the partial skull⁴ was found at Malapa, in the Cradle of Humankind World Heritage Site, the same site where the partial skeletons of the new early hominin species, Australopithecus sediba, were discovered in 2010.

 

"Baboons⁵ are known to have co-existed with hominins at several fossil localities in East Africa and South Africa and they are sometimes even used as comparative models in human evolution," says Dr Christopher Gilbert (Hunter College, CUNY), lead author of the study.

 

The skull, found during excavations⁶ for A. sediba, confirms earlier suggestions that the fossil baboon species to which it belongs, Papio angusticeps, was in fact closely related to modern baboons, and quite possibly the earliest known members of the modern baboon species Papio hamadryas.

 

Modern baboons (genus Papio) are typically divided into a number of populations recognised as either species or subspecies spread all throughout sub-Saharan Africa and into the Arabian Peninsula. Despite their evolutionary success, modern baboon origins in the fossil record have not well-understood or agreed upon.

 

"According to molecular⁷ clock studies, baboons are estimated to have diverged⁸ from their closest relatives by ~1.8 to 2.2 million years ago; however, until now, most fossil specimens⁹ known within this time range have been either too fragmentary to be definitive¹⁰ or too primitive¹¹ to be confirmed as members of the living species Papio hamadryas," says Gilbert.

 

"The specimen from Malapa and our current analyses help to confirm the suggestion of previous researchers that P. angusticeps may, in fact, be an early population of P. hamadryas."

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