According to the paleontologists study of dinosaur intelligence they were once regarded as being extremely stupid animals but have been largely appraised more generously since the Dinosaur Renaissance.
This newfound optimism for dinosaur intelligence has led to highly exaggerated portrayals in pop cultural works like Jurassic Park.
Paleontologists now regard dinosaurs as being very intelligent for reptiles, but generally not as smart as mammals.
Popular misconceptions of dinosaur neurology include the concept of a second brain regarding in the pelves of stegosaurs and sauropods.
Encephalization quotient (EQ)
The type of approximation used for the intelligence of dinosaurs as well as with other organisms is their encephalization quotient or brain-to-body mass ratio.
This measure assumes that the animals with the greatest EQs and proportionally largest brains were the most intelligent.
By this measure the most intelligent dinosaur were small–bodied theropods ("coelurosaurs") like Troodon ,followed by the dromaeosaurid dinosaurs (the "raptors," which included Dromeosaurus, Velociraptor, Deinonychus, and others) with EQs of about 5.8.
The dinosaurs with the smallest EQs were basal sauropodomorphs ("prosauropods"), with EQs of about 0.05