Old world monkeys have surprisingly complex brains says a new study out of Duke University. A team of evolutionary anthropologists lead by Lauren Gonzales scanned the brain of an ancient monkey known as Victoriapithecus.
The skull, found in Kenya in 1997, was scanned using micro CT-scans, which revealed a wrinkled and well-defined brain. The team conducting the study even said parts of the brain are more developed than those of currently living monkeys.
The scan revealed the brain volume was only about 36 cubic centimetres, less than half the volume of living monkeys. However, the small size doesn’t mean it’s not complex. The researchers found that the olfactory area was three times larger than expected. This region of the brain is responsible for scent so it is expected that this monkey would have had a very strong sense of smell.
According to Lauren Gonzales, the olfactory part of the brain if very small in living primates compared to the size of the rest of the brain but this is not the case with Victoriapithecus. She also said that as vision improved in modern primates, the olfactory region shrunk but the team believes Victoriapithecus had both a strong sense of smell and vision.
There is still debate among the scientific community about whether brain complexity or size came first in primates. This study suggests complexity was first to arise and primates became more intelligent and began to evolve in hominids and eventually humans.
Gonzalez says: “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.”
The study was published in the journal Nature.