A story in the UC Berkeley News details how dinosaurs were probably much different than we have imagined.  50 years ago, scientists had a much differernt view of dinosaurs as slow, dumb animals.  Then, came John Ostrom, Bob Bakker with their insights comparing dinosaurs to modern animals. Those viewpoints led to the Jurassic Park view of the dinosaur world.  A Berkely Voices podcast was the basis of this story.  You can find it here.

For a long time, paleontologists thought that the famous, long-extinct apex predator, the Tyrannosaurus rex, may have chased its prey at high speeds. Children’s books and movies often showed the dinosaur sprinting at a terrifying pace; you might remember scenes from the 1993 film Jurassic Park in which a massive T. rex chases characters who are escaping in a Jeep that they’re driving as fast as they can.

But in the past few decades, paleontologists have found that this wasn’t exactly accurate — and it’s one of a number of ideas we’ve long held about these ancient creatures that are being reshaped by modern science. 

“After really sort of ground truthing, figuring out how much bone and tissue needs to be on the animal to reach a particular speed with enough power, people realized Tyrannosaurus probably didn’t run more than 20, 25 miles per hour,” says Jack Tseng, a UC Berkeley vertebrate paleontologist and functional morphologist.