15 feet tall and weighing six tonnes, the Tyrannosaurus Rex would have been the largest carnivore in its environment, thus earning the name “Tyrant Lizard King”. Though fossil discoveries have shown that larger land-based carnivores existed in other regions and eras, none have usurped the place of the T. rex in popular culture. After all, it’s a movie monster that actually existed.
But for almost as long as the T. rex has held that place, experts have debated whether it was truly as fearsome as popular portrayals of it suggest. Did the king of the dinosaurs hunt its own food, or let others do its killing for it?
Hunter or Scavenger?
Arguments for the T. rex being a scavenger center around its physical qualities. Its tiny arms would have been ill-suited to subduing prey, and it had poor eyesight when you’d expect a predator to have enhanced senses. It may not have been as fast as previously believed either, with scientists estimating speeds of 10-20 mph rather then the 50-60 mph that has sometimes been suggested.
On the other hand, the power of its bite and the size of its teeth would have compensated for the uselessness of its arms, while its large olfactory lobes suggest that it had a strong sense of smell to make up for its limited vision. Of course, that sense of smell could have been used to track down prey or carrion, depending on which side of the argument you take.
As for its speed, whether or not that was a factor depends on its methods of hunting, as not all predators rely on chasing down their prey. Though its large size makes it difficult to imagine the T. rex utilizing stealth, it may have focused its efforts on the slower, weaker members of a herd, or on large prey not much faster then itself. There’s even evidence to suggest it engaged in duels with fellow tyrannosaurs, in which the loser literally provided the winner with dinner.
Another argument in favor of the Tyrannosaurus Rex being a hunter is that it would not have been very successful as a scavenger, due to the presence of smaller carnivores that could cover 60 times as much ground in a day. Using predator relationships in the Serengeti as an ecological model, scientists from the Zoological Society of London showed that such competition would have made it difficult for the T. rex to survive as a species if it relied solely on scavenging.
Evidence of T. rex Attacks
The discovery of a fossilized Hadrosaur spine with a Tyrannosaur tooth embedded in it has provided some of the strongest evidence yet that the T. Rex did indeed pursue live prey.
The Hadrosaurs were duck-billed herbivores that traveled in herds. They were the Cretaceous period’s equivalent of deer, in that they were extremely populous, but appeared to have little defense against carnivores other then running for their lives.
It seems that this particular Hadrosaur succeeded in doing exactly that, as the bone shows signs of healing from the bite. More importantly, the bone-growth proves that the creature was alive when the T. Rex attempted to make a meal out of it, and the tooth lodged in its tail indicates that it was fleeing its attacker.
Fossilized remains of T. rex meals have been discovered in the past, but it’s never been clear whether the victim was alive or dead when feeding began. In this case, the victim was alive and managed to remain so. Though the T. rex would have regrown the lost tooth, who knows how much longer its hunger would go unsated?
Why not both?
Many have grown tired of the debate, and consider it to be a non-issue anyway. “Whether or not T. rex hunted is the most-asked question I get at talks and on the radio. And that makes me sad” tweeted Brian Switek, author of “Written in Stone: Evolution, the Fossil Record and Our Place in Nature”.
Observations of the legendary hunters of our time, such as lions and wolves, have revealed them to be more then willing to accept leftovers if the opportunity presents itself. Thus the idea that a carnivore must be “hunter” or “scavenger” is in itself a false premise.
Using the physical qualities of the T. rex as a basis for the argument is also misleading. The vulture has similar physical qualities to the eagle, yet one is a scavenger and the other a bird of prey.
The general consensus among paleontologists is that the Tyrannosaurus Rex, like many other carnivores, ate whatever happened to come its way. Dead prey. Living prey. It’s all just meat to the T-Rex.
