Is it true that dinosaurs had very small brains in relation to their size?

Zbeckabee

It is commonly said that dinosaurs had unusually small brains and must have been very stupid. Ostrom and Jerison say dinosaur brains were appropriate for reptiles once the negative allometric (scaling) relationship is taken into account. Data from dinosaurs added to the brain size/body size graph only extend the "lower vertebrate" polygon into larger body sizes without distorting its shape. http://fossilnews.com/1998/brain.html Mar 17 10, 6:42 AM

star_gazer

In general, dinosaurs had small brains. Sauropods were the largest of dinosaurs, yet the size of their brains is comparable to that of a modern dog. Given the sauropod's enormous body size, the ratio of brain mass to body mass is the smallest of any of the dinosaurs. The dinosaur with the smallest brain was Stegosaurus. It is difficult to imagine any animal functioning on a brain the size of a golf ball or walnut, yet Stegosaurus apparently thrived during its time. Stegosaurus is also famous for a "second brain" in its hip region that may have controlled its hind legs and tail. Everything that is known about dinosaur brains is based on fossilized casts that formed when mud filled their skulls. A fossilized cast is a nearly perfect stone replica of a dinosaur brain -- minute details such as nerve endings are visible. Not all dinosaurs had minuscule brains. In relation to their body mass, ceratopsians had relatively large brains, as did such theropods as the dromaeosaurids. Dromaeosaurids, in fact, are considered to be the smartest of dinosaurs, and they were probably at least as intelligent as the Emu (a modern, ostrich-like bird). http://www.dinodatabase.com/gloss/DNOGLOSD.asp Mar 17 10, 6:42 AM