Scientists Discover Largest Dinosaurs Ever Had Tennis Ball-Sized Brains

Confirming the whispers of dweebs in gym classes the world over that the biggest guys are often also some of the dumbest; the Ampelosaurus, an "advanced" member of the largest group of dinosaurs ever, had a relatively minuscule brain, researchers found.

Click here to see a picture of the Ampelosaurus

Scientists discerned the findings after discovering the dinosaur's 70-million-year-old fossilized skull in 2007 in Cuenca, Spain, in the course of constructing a high-speed rail track connecting Madrid and Valencia, LiveScience.com reported. The Ampeleosaurus was a sauropod, long-necked, long-tailed herbivore, and was the largest creature to ever walk on Earth. Or, more specifically, the reptile was a kind of sauropod epically referred to as a titanosaur, many if not all of which were covered in armor-like scales all over their bodies.

Sauropod skulls are usually very fragile. Few have survived in good enough condition for scientists to be able to learn much about their brains. But by scanning the interior of the skull through CT imagining, researchers were able to develop a 3D reconstruction of the Ampeleosaurus' brain, which was about the size of an average tennis ball.

"This saurian may have reached 15 meters (49 feet) in length; nonetheless its brain was not in excess of 8 centimeters (3 inches)," study researcher Fabien Knoll, a paleontologist at Spain's National Museum of Natural Sciences, said in a statement.

The first sauropods first appeared on Earth around 160 million years earlier than this fossil, according to LiveScience.

"We don't see much expansion of brain size in this group of animals as they go through time, unlike a lot of mammalian and bird groups, where you see increases in brain size over time," researcher Lawrence Witmer, an anatomist and paleontologist at Ohio University, told LiveScience. "They apparently hit on something and stuck with it - expansion of brain size over time wasn't a major focus of theirs."

Scientists have wondered for years just how the largest land animals that ever lived managed to so with such puny brains.

"Maybe we should flip that question on their end - maybe we shouldn't ask how they could function with tiny brains, but what are many modern animals doing with such ridiculously large brains. Cows may be triple-Einsteins compared to most dinosaurs, but why?" Witmer said.