One thing to add to these rules is connected to the role of the brain and nervous system. Dinosaurs had plenty of muscle mass, but very small brains for their size. Muscle has memory and nerves, and is therefore not too far from a rudimentary form of brain matter. The large dinosaur could depend on the computer power of their muscles and brain stem, to do most of his simple needs; routine walking or chewing, with this constant activity adding a potential to amplify their small brain, through feedback loops, pushing the brain forward.