To understand how some creatures evolved, you need to see how their brain developed over millions of years. That's now possible thanks to some clever use of scanning technology.

This 119 million year old fish, Rhacolepis, is the first fossil to show a 3D preserved heart which gives us a rare window into the early evolution of one of our body’s most important organs.
Dr John Maisey, American Museum of Natural History in New YorkApril 19, 2016

Life as we know it is carbon-based, that is, organic. These organic molecules containing mostly carbon and hydrogen are delicate to the ravages of time, relatively speaking. They aren’t usually preserved…