Question 2 of 21

What kind of gait did the Tyrannosaurus rex (T. rex) have?

... The T. rex had a bipedal gait, meaning it walked (or ran) on two feet, had arm-like forelimbs and a mouth full of knife-sharp teeth. All this contributes to its image as a scary monster.

Question 3 of 21

Where did the T. rex rank in its ecosystem?

... The T. rex always ranked as the largest carnivore in its ecosystem. Its physical characteristics also lend some credence to the idea that it was an aggressive predator.

Question 4 of 21

What kind of teeth did the T. rex have?

... Not only were the T. rex's teeth dagger-like and enormous, they were serrated, making them ideal to cut through meat.

Question 5 of 21

What do scientists estimate was the biting power of a T. rex's jaws?

... Scientists estimate, based on an analysis of skull fossils, that the biting power of a T. rex's jaw is about 3,822 pounds to 6,788 pounds (183,000 newtons to 325,000 newtons).

Question 6 of 21

What do long thigh bones in an animal indicate?

... The T. rex had long thigh bones, indicating good running endurance. This means that the T. rex might have run over long distances for long periods of time, implying an ability to prey on other dinosaurs.

Question 7 of 21

What was the purpose of the triceratops's bony frilled neck?

... The Triceratops's neck would likely have been a defense mechanism to protect them from predators. It could also have been used to attract mates.

Question 8 of 21

Where did the triceratops get its name from?

... The triceratops got its name from the three horns atop its head.

Question 9 of 21

When did the idea that the T. rex may have been a scavenger originate?

... This idea originated in the 1900s. Today, the most famous proponent of the theory is John R. Horner of the Montana State University.

Question 10 of 21

Which theory is the basis for the theory that T. rex may have been a scavenger?

... The idea that the T. rex may have been a scavenger is based on the theory that birds originated from dinosaurs. Even the largest birds are scavengers, not predators, so perhaps their ancestors weren't predators either.

Question 11 of 21

What was the tooth structure of a T. rex's bite?

... When a T. rex closed its jaw, the lower teeth met the insides of the upper teeth. This would have given them upward force from the inside and downward force from the outside, perfect for breaking bones. This indicates they might have eaten by bone picking, as scavengers do.

Question 12 of 21

What would a T. rex's large nasal passages have served for according to the scavenger theory?

... T.- rex's large nasal passages would have been useful for smelling carrion from far distances. This supports the scavenger theory that they ate what they found, not what they killed.

Question 13 of 21

What is coprolite?

... Coprolite is fossilized dinosaur dung. When scientists examined it, they found traces of bone shards, indicating that T. rex may have eaten by picking over bones, like a scavenger.

Question 14 of 21

What aspects of the T. rex's physical structure would have made running a challenge?

... The T. rex's massive size and short forearms would have meant that it would be unable to break its fall should it trip while running, and so would most likely sustain life-threatening injuries if it fell.

Question 15 of 21

What do studies suggest was the T. rex's speed while running?

... Studies suggest that the T. rex's speed while running was 22 mph (or 10 meters per second), indicating that it couldn't run very fast. Also, researchers have suggested that their legs would not have been able to support enough muscle for fast running.

Question 16 of 21

How much carrion would have been needed for a dinosaur to live on?

... Graeme D. Ruxton and David C. Houston of the University of Glasgow estimated that for a dinosaur to have survived on carrion alone, there would need to have been the amount there is today in the Serengeti. They made this calculation by comparing the energy required to find food and the energy food provided them with.

Question 17 of 21

What is further evidence that the T. rex may have been a predator?

... Further evidence comes from evidence of bite marks on other dinosaurs that match the jaws and bite of a T. rex.

Question 18 of 21

What does Kenneth Carpenter, of the Denver Museum of Natural History, say about the T. rex's arms?

... Kenneth Carpenter suggested, based on the positioning, shape and size of the shoulder blades and arm bones, that the T. rex's arms may have looked puny, but were actually very strong.

Question 19 of 21

Which animals preys on other animals despite not having arms?

... Snakes do not have arms, but still manage to prey on other animals larger than them. This is used to support the idea that a T. rex's seemingly puny arms need not have stopped it from attacking other dinosaurs.

Question 20 of 21

What else would a T. rex have bitten?

... A T. rex likely used its teeth against its own kin, as evidenced by T. rex teeth marks on the skulls of other T. rexes. The reason for this is unknown; it could have been mating rituals, fights over territory, or some other social behavior.

Question 21 of 21

What do many scientists conclude about the T. rex?

... Scientists conclude that the T. rex was most likely an opportunist, eating carrion when it was available and hunting when it was not.