Victoriapithecus is an ancient species of primate known from a single fossil, discovered near Lake Victoria in Kenya. It is the oldest-known monkey fossil from the Old World, living 15 million years before our own time.
Duke University researchers have created the first detailed visualization of the cranial cavity of the species, finding the ancient creatures had small, complex brains. A computer was utilized to develop a three-dimensional representation of the brain of the long-extinct animal. Analysis of the model suggests that primate brains could have evolved a structure full of wrinkles before growing in size. These creatures possessed a tiny brain compared with their body size, around 2.2 cubic inches, roughly half the size of similarly-sized monkeys living in the world today. The difference in volume is roughly comparable to comparing a plum to an orange.
Still, despite this small size, the creatures likely had some significant advantages in the fight for survival. The olfactory bulb, which manages and controls the sense of smell, was found to be three times larger than expected.
"It probably had a better sense of smell than many monkeys and apes living today. In living higher primates you find the opposite: the brain is very big, and the olfactory bulb is very small, presumably because as their vision got better their sense of smell got worse. But instead of a tradeoff between smell and sight, Victoriapithecus might have retained both capabilities," Lauren Gonzales of Duke University said.
Due to the lack of detailed fossils of primates from around the time this creature lived, biologists have long debated if primate brains grew in size or complexity first.
Victoriapithecus was found in 1997, one of the few primate specimens ever recovered from the era in which this animal lived. The fossil is currently in the collection of the National Museums of Kenya, located in Nairobi.
Investigators believe their study could help answer unresolved questions concerning the evolution of brains in primates, including our own species.
"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 said.
Development of the 3D brain model and analysis of what the ancient creature can teach us about the evolution of brains in primates was published in the journal Nature Communications.
