Oldest Fossilized Brain Found in Fish

A 300-million-year-old fossilized brain has been discovered by researchers studying a type of fish that once lived in what is now Kansas and Oklahoma.

Researchers report in the online edition of Proceedings of the National Academy of Science that the brain was discovered in a fossilized iniopterygian from Kansas, which they had sent for scanning at the European Synchrotron Radiation Facility in Grenoble, France.

Iniopterygians are extinct relatives of modern ratfishes, also known as ghost sharks.
The scan found a fossilized blob inside the braincase and closer study revealed it was the fossilized brain of the ancient creature.