Scientists took advantage of a perfectly fossilized monkey skull to examine and determine the structure of its brain. The team of paleontologists used CT scanners for their procedure. It is worth mentioning that the age of the skull was evaluated to be around 20 million years old.
The investigation aimed to understand better how brains evolved over time. And as there are not many fossilized human skulls or brains to examine, primate fossils are just as good. What the researchers look for are the marks the brain leaves on the cranial walls, which give information about the shape and structure of the brain.
As it is commonly known, the age of the Great Apes, which is a taxonomic family of primates that include four genera among which is the Homo genus, appeared around 20-15 million years ago. The fact that the monkey skull is about 20 million years old could show the paleontologists how primate brains were before the first ancient humans evolved.
Evolution Of Primates Detailed Thanks To A Fossilized Monkey Skull Of 20 Million Years Old
The evolutionary tree of the anthropoids divides into two groups: the New World monkeys, or the Platyrrhini (in South America) and the Old World monkeys, or Catarrhini (in Africa). Humans have descended from Old World monkeys. The fossilized monkey skull found by paleontologists, called Chilecebus carrascoensis, belongs to the Platyrrhini group and is believed to be among the first that departed from their common ancestor.
Its brain did not weight more than 8 grams, but, despite this, it presented some complex folding. What’s more, the researchers could also assess the size of the primate’s olfactory bulb and shape of the optic canal and optic nerve. These measurements and discoveries lead the paleontologists to conclude that the brain of monkeys did not evolve as an entire unit, but happened gradually.
Even though more skull fossils (and better preserved) are needed to make more than assumptions, the researchers were able to add find out what characteristics have been lost to evolution, which evolved from an ancestor and which developed independently, all that thanks to this recently discovered fossilized monkey skull.