It's been a long time—66 million years!—since the Cretaceous Period ended in explosive fashion, so there's a lot we don't know about our predecessors atop the food chain, the dinosaurs. Were they hot-blooded or cold-blooded, fast or slow, pack animals or lone hunters? What color were they, and what did they sound like? Could you really use one to make a record player, like the Flintstones did? Luckily, our Jeopardy! correspondent Ken Jennings has just published his seventh Junior Genius Guide, this one all about the dinosaurs! He's here all month to straighten us out on all the Mesozoic misinformation we thought we knew.
The Debunker: Did Tyrannosaurus Have Scrawny Little Arms?
The lamestream media, from The Far Side to the Toy Story movies, has spent the last few decades trying to convince us that the mighty prehistoric carnivore Tyrannosaurus rex should feel bad about its body. Specifically: that it skipped too many arm days at the Jurassic gym.
But don’t get too cocky if you're arm-wrestling a T. rex. Those arms may look wimpy in comparison to a tyrannosaur's seven-ton frame, but the thick cortical layer of the forelimb bones suggests to scientists that the muscles attached there were ripped. A 2002 study estimated that Tyrannosaurus could curl an impressive 430 pounds with each arm, which probably came in handy whether the prehistoric giant was grappling with doomed prey or with a mate.
While I'm correcting tyrannosaur untruths, I should probably make you aware that T. rex also didn't stand the way you probably imagine from museum skeletons and Godzilla movies. The first 1905 reconstructions of Tyrannosaurus showed it standing upright and dragging its tail behind. But we've known for over twenty years that its posture was much worse than that. In fact, T. rex's spine was actually within 10º of horizontal! And don't believe the Jurassic Park hype about holding still to avoid a tyrannosaur attack, because Tyrannosaurus skulls seem almost designed for amazing vision. Their visual acuity was probably about 13 times better than a human's, which means they could see objects up to four miles away, and with a field of vision wider than a hawk's. Standing still in front of a T. rex would have been a recipe for suicide, not a brilliant escape maneuver. Keep your advice and your dodgy American accent to yourself, Sam Neill.
Quick Quiz: What was the T. Rex song "Get It On" renamed when it became a hit in the U.S.?
Ken Jennings is the author of eleven books, most recently his Junior Genius Guides, Because I Said So!, and Maphead. He's also the proud owner of an underwhelming Bag o' Crap. Follow him at ken-jennings.com or on Twitter as @KenJennings.