With over a century of study and a fair amount of fossil data to go on, scientists have a lot to discuss about T. rex; thanks to its dramatic frame and name, so does everyone else. By far the most popular dinosaur, Tyrannosaurus has attained the status of a legendary icon, for better and worse. So without further ado, enjoy these tidbits:
- The name “Tyrannosaurus rex“roughly translates to “King of the Tyrant Reptiles.”
- You may have heard of a “controversy” about whether Tyrannosaurus scavenged or actively hunted. One of the only scientists defending the scavenger model was John Horner, a hadrosaur specialist. Tyrannosaur and theropod (the group that includes the meat-eating dinosaurs) specialists favored active hunting because of Tyrannosaurus’ size, build, and overall body design. The debate died down when someone discovered a duck-billed Edmontosaurus with a bite taken out of its tail—the bite marks perfectly matched the teeth of a Tyrannosaurus, but they also showed signs of healing, which proves that it survived a T. rex attack. In reality, though, no animal exclusively scavenges or hunts. Like any other apex predator, T. rex would have acted like the king of its domain: it took whatever it wanted—living or dead—and exacted “taxes” from the other carnivores in its environment by stealing their kills.
- The largest part of a T. rex’s brain processed its senses, particularly smell. Some scientists estimate that its sense of smell rivaled a shark’s or a vulture’s—two modern animals with incredible sniffers (some sharks can detect blood in one part per billion, and a vulture can whiff a carcass from over a mile away). Overall, its brain design resembled both birds’ and crocodiles’, which means that with the right incentive a T. rex might have taken training. Jurassic World actually suggests this with the road flare that signaled food, a behavior pattern the rex would have learned when Malcom’s flare led it to a certain tasty lawyer.
- One hypothesis suggests Tyrannosaurus females may have outweighed the males. Though the case for determining T. rex sex remains uncertain, what evidence we currently have suggests that T. rex genes, like those of eagles and other modern raptors, may have favored larger girls since they need more resources for producing the next generation. A difference in size may have forced males and females to tackle different prey within the same area. Scientists have also found a telltale pattern in the thigh of one T. rex that resembles one found in modern mama birds. A female bird will cannibalize calcium from her own thigh bone to create the hard shell for her eggs. If T. rex did likewise, their eggs probably featured hard shells too.
- The comically tiny arms of the Tyrannosaurus packed a surprising wallop: each could curl roughly 400 lbs! They were so muscle-bound that they could hardly move. Scientists still don’t know exactly what the animal would have used such arms for, but the fact that it had sharp, functional claws suggests that it used those tiny arms for something. Current theories include holding struggling prey, usage as meat hooks for keeping floppy bits of carcass from catching in the underbrush, supplemental transport for T. rex hatchlings (if they followed a parental instinct like alligators or birds), levers for helping the animal to its feet (unlikely), or some sort of role in mating. Robert Bakker, a scientist known for some unusual theories, even suggests they tickled each other, or used those claws for grooming each other. Like other animals, its arms probably served a variety of functions.
- Since the discovery of Yutyrannus, a distant cousin of T. rex that sported a shaggy skin covering, pictures of fluffy tyrannosaurs have proliferated throughout paleontology media. Proponents of this model claim that since Yutyrannus more closely resembled it and Tyrannosaurus‘ common ancestor, its shaggy coat makes the best model for Tyrannosaurus‘ overall appearance. However, fossil skin impressions from T. rex and its closest relatives exhibit a more pebbly appearance typical of scales found on numerous other dinosaurs.