Mammals’ large brains evolved for smell

A highly developed sense of smell kick-started the development of mammals’ big brains.

Scientists used very high-resolution scanning to study the skulls of two of the earliest known mammal species.

Comparing the shape of their brain cases to those of slightly earlier animals, or “pre-mammals”, revealed that the first brain areas to over-develop were those associated with the sense of smell.

The findings are published in Science.

An improved sense of smell may have allowed our tiny, furry ancestors to hunt at night.

The researchers were able to create 3D images of prehistoric animals’ brains using the latest computed tomography, or CT, scanning methods.