A fossil from the Ruvuma region holds one of the world’s oldest known tumors.
The type of benign tumor researchers found still occurs in mammals — it’s commonly known as an odontoma — but this one was from 255 million years ago, before mammals existed.
The tumor was found by accident while University of Washington researchers examining the jawbone of a pre-dinosaur sabre-toothed creature which roamed the Ruhuhu basin in the Ruvuma region.
This find also proves that tumors, which rarely fossilize, also happened to the early ancestors of mammals.
“There was no indication that there was a tumor in this jaw. It looked normal before we cut it open. It was pure luck that we found the tumor,” says University of Washington paleobiologist Megan Whitney, speaking to Reuters.
The animal belonged to a carnivore family called gorgonopsians, a hybrid mammal-reptile that could grow up to 10 feet long long.
The oldest known tumor is a case of cancer reported in a fish 300 million years ago.