Dino Intelligence: Dim to Somewhat Smart

Nearly matching ornithomimids in mental swiftness, according to Gao, were the troodontids, at 0.7 EQ. Troodontids were small to medium-sized long-legged dinosaurs with sickle-like claws. They too shared many characteristics with modern-day birds.

Iguanodons, at 0.5 EQ, and hadrosaurids at 0.47 EQ round out the more complex-behaving dino group. "Complexity" for dinos was also linked to birds, as these more sophisticated animals tended to nest, follow bird-like sleeping behaviors and to engage in greater parental doting. Such behaviors, Gao said, "are evolved among those smart animals under the control of a powerful brain."

The researchers were surprised to discover that many top predator dinosaurs, such as Tyrannosaurus rex and allosaurids, had lower EQ values than iguanodons and hadrosaurids.

"I guess that we have to say it is not the body size, but the relative brain size that reflects how well the dinosaur species adapted to their living environment," Gao explained. "It is all about the survival of the fittest."

Slow-Witted Dinosaurs

Brawn definitely did not indicate dino braininess. Wright concluded that many big dinosaurs fell "below the (existing ground bird EQ) range and the sauropods remain the least intelligent."

At the very bottom of the EQ ratings is Diplodocus, with a meager 0.05 EQ. One of the longest known dinosaurs, Diplodocus could measure around 90 feet in length. Twenty feet of that was neck, topped off with a tiny head and an even tinier brain case.

This Jurassic dino predated some of the more complex-behaving earlier dinosaurs. Thinking again of technological innovations, it seems that evolution can produce brainier models as time goes on. Thomas Wagner, program director for the National Science Foundation's Antarctic Earth Sciences fund, explained the phenomenon to Discovery News.

"Think of it like this," Wagner said. "Crylophosaurusellioti (a recently discovered Antarctic dino), at 185 million years old, was a distant ancestor to T. rex, which died out 65 million years ago. I can imagine it would have gotten a lot more sophisticated in 120 million years."

Star Trek Truth?

Dale Russell, curator of vertebrate fossils at the National Museums of Canada, also theorizes that intelligence may improve over evolutionary time. In the 1980's, he modeled what might have happened if troodon, a genus of a relatively small, bird-like dinosaur from the Late Cretaceous Period, had survived the K-T extinction event.

Not unlike the Star Trek Saurians, Russell's modern day troodons would have stood upright -- to hold and balance their brain-heavy heads -- and would have had big eyes, the better with which to see, and shoulders that could have permitted throwing objects.

While history stopped troodon evolution dead in its tracks, modern science is revealing that many dinosaurs were not complete airy boneheads, as their now-empty skulls suggest. As Wright concluded, "Dinosaurs were not nearly as intellectually challenged as once thought."

Related Links:

Jen Viegas' blog: Born Animal

Were Dinosaurs Bird Brains?

How Stuff Works: Dinosaurs