Brain size (or its proxy, encephalization quotient) usually varies allometrically with mass -- larger creatures need larger brains to control their larger bodies, apparently.
Dinosaurs are popularly known as small-brained. While this certainly doesn't hold in general -- theropods and especially birds were particularly intelligent -- but sauropods and thyreophorans (ankylosaurs and stegosaurs) seem to have preposterously small brains. How were they able to control their large bodies with such small brains? Are there modern animals with similar proportional brain size, and if so does that give any clues as to how these dinosaurs functioned?