In A Book I Read Stegosaurus Had The Brain The Size Of 4 Or 5 Walnuts.Is This True?
from Austin V., age ?, ?, ?, ?; July 10, 2001

MIKE: The main part of the brain of Stegosaurus was slightly larger than a single large walnut. Although this may seem quite small based on human standards, it was what you could expect for a brain in a typical Jurassic herbivorous dinosaur (or certain politicians). Some scientists have plotted a graph with the brain mass of dinosaurs on the Y-axis and the body mass on the X-axis. The result is a series of points than roughly fall on a single line. This allows us to predict the brain size for dinosaurs of a known mass. The relationship between the EXPECTED brain size of a dinosaur versus the ACTUAL brain size is called the "encephalization quotient" or EQ. (Not to be confused the far less accurate IG.) The EQ of theropods is highest among the dinosaurs with stegosaurs at the lower end. This made stegosaurs just brainy enough to get along in their world.