Scientists have discovered that the brain of the Old World monkey that lived about 15 million years ago was more complex than previously thought inn spite of its small size. The research was published in the journal Nature and it was conducted by researchers from the Max Planck Institute for Evolutionary Anthropology and Duke University.
Also known as Victoriapithecus, the ancient Old World monkey was a family of primates which macaques and baboons were part of. The skull was unearthed in Kenya (Lake Victoria) in 1997. Researchers say that the brain of the monkey was small but well defined and moreover it was more complex than the brain of its descendants.
The researchers used a high-resolution X-ray imaging and created a 3D model of the Old World monkey’s brain. They discovered that its brain was about half the size of the brain of monkeys nowadays. However it had an unexpected level of complexity indicated by the large number of folds and wrinkles. Another peculiarity was the fact that the olfactory bulb which the fossil presented was three times larger than what was normally expected.
This suggests that the Old World monkey had a more developed sense of smell than modern monkeys of today. Monkeys as we know them today, on the contrary, have a small olfactory bulb and a larger brain. Scientists theorize that this was a result of the fact that in time the monkey’s sight improved whereas its sense of smell worsened.
The co-author of the study Lauren Gonzales from Duke University remarked:
“In the part of the primate family tree that includes apes and humans, the thinking is that brains got bigger and then they get more folded and complex. But this study is some of the hardest proof that in monkeys, the order of events was reversed — complexity came first and bigger brains came later.”
Gonzales also explained that the research team used Micro-CT scan in order to establish the size of the brain compared to the body of the monkey and discovered that its volume was 36 cubic centimeters.
This study offers insight into how cognitive functions developed in the case of early primates and also offers new information about how complex the monkey brain was in relation to size. So far very little was known about the Old World monkey because the number of fossils is very small.
Image Source: Sci-News