No one really knows the true size of dinosaur brains because, as with all soft parts of dinosaurs, brains did not survive the fossilization process. Therefore, scientists can only infer the size of the animals’ brains by examining the brain case: the part of the skull housing the brain. They have found that different dinosaurs had different sized brains. For example, sauropod brains were small in comparison to their body weight, whereas some dinosaurs, such as the Velociraptor, had very large brains in comparison to their body weight.