Most everyone is familiar with the idea that huge dinosaurs had brains the size of a walnut. But where did this unflattering comparison come from? Witmer, who has tried to get at the origins of the idea, says the earliest example anyone has turned up so far is in Jennie Irene Mix’s 1912 book Mighty Animals, which says that the famous Jurassic sauropod Diplodocus “had a brain that was not much bigger than a walnut.” The meme didn’t really catch on until 1945, though, when paleontologist Edwin Colbert said that the armor-plated Stegosaurus also had a brain the size of the edible seed.

Witmer was reminded of the old saying when news source LiveScience covered