Tyrannosaurus Rex has so often been portrayed in Hollywood movies as a swift, merciless, savage hunter--witness that Porta-Potty-chomping speed demon of the first Jurassic Park flick--that it's easy to lose sight of the fact that ravenous Rexes are strictly a Hollywood invention, and may or or may not bear any connection to the actual truth. (See 10 Facts About Tyrannosaurus Rex, a Brief History of Tyrannosaurus Rex and a gallery of Tyrannosaurus Rex pictures.)
The main reason so many paleontologists--and so many Hollywood moguls--subscribe to the fearsome hunter theory is Tyrannosaurus Rex's teeth, which were large, sharp, and extremely numerous, as well as the enormous size of Tyrannosaurus Rex itself. It seems unlikely that nature would have evolved such a huge set of choppers for a dinosaur that feasted on already dead (or dying) animals, but then again, evolution doesn't always operate in a strictly linear or logical fashion.
There are four main strands of evidence in favor of the theory that Tyrannosaurs Rex happened upon, rather than hunted down, its food:
- Tyrannosaurus Rex had small, weak, beady eyes, where you might expect an active predator to possess super-sharp vision.
- Tyrannosaurus Rex had famously small, almost vestigial arms, which would have been near-useless in a close grapple with live prey.
- Tyrannosaurus Rex was none too fast, more a lumbering lummox than the sleek predator of Jurassic Park. It was once thought that this tyrannosaur could chase down prey at a blistering 40 miles per hour, but today, a relatively pokey 10 mph seems to be a better estimate.
- Most convincing of all to many scientists, analysis of Tyrannosaurus Rex skulls shows the presence of unusually large olfactory lobes, which would have been ideal for catching the scent of rotting carcasses from miles away.
While the Tyrannosaurus Rex-as-scavenger theory has been surprisingly quick to catch on in the scientific community, not everyone is convinced. In fact, this may not even be an either/or type of argument: like other opportunistic carnivores, T. Rex may have actively hunted at some times, and at other times it may have feasted on prey that had either died of natural causes or already been pursued and killed by other, smaller dinosaurs. Pending decisive fossil evidence, we may never know for sure.
