This is my first blog post so I thought I’d start out with talking about my favorite dinosaur-Tyrannosaurus rex.
Basic Facts And Size:
T. rex, which was one of the largest theropods ever, being only a little smaller than Spinosaurus and similar in size to Giganotosaurus, belonged to the Tyrannosaur family. Its name means Tyrant Lizard King. They were 40-43 ft. long, could reach heights (at the head) of 18-20 ft., and weighed 6-8 tons. The strength of T. rex’s neck and back allowed it to lift up 4-5 tons.
The skull of T. rex is very long (around 5 ft.) and also bulky. To lighten the load of this extremely large head there were numerous fenestrae (large openings of the bone) along the top and sides of the skull. Muscles were attached to the fenestrae strengthening the skull and adding more power to the 4 ft. long jaws giving it a more powerful bite force of around 6.5 tons.
Senses And Intelligence:
T. rex’s eyes, unlike most theropods, faced forwards giving it excellent 3D vision about 6 times better than a human’s. The region of the brain dedicated to smell (called the olfactory bulbs) in T. rex were very large giving it an excellent sense of smell. Scientists can estimate the size of the brain from the internal cavity of the skull, and from this they can make an internal brain cast from injected foam or a model using MRI or CAT scans. T. rex probably had the intelligence of a house cat, which is smart for a dinosaur. They may also have been able to feel vibrations in the ground with their feet, allowing them to know where prey was. With this intelligence and these senses T. rex could easily locate prey.
T. rex teeth were 12 in. long (only 8 in. stuck out of the gum) and had small, knife-like serrations, but the teeth are anything but blade-like. They are shaped more like railroad spikes and when slammed down on prey with 6.5 tons of force they resulted in a powerful puncture-like bite. Instead of slicing through flesh like other theropod teeth, T. rex teeth held on to the flesh of prey and ripped off chunks of over 150 lbs. This could be devastating to its prey. The T. rex wouldn’t even need to attack the dinosaur again because it would die of loss of blood and shock from the wound.
Legs And Arms:
The legs of T. rex appear to have been very muscular allowing it to run about 15-20 mph. and able to take strides of 16.5 ft. It may also have been able to kick with its feet but would have to be careful because it would be standing on one leg and could be easily knocked over. Despite the strength of their legs, T. rex could most likely not jump. The strangest thing about T. rex is its tiny arms. They aren’t actually that small because, after all, they are 3 ft. long, but compared tho the rest of the body they are puny. Now we must realize that since T. rex had a large head it needed to counterbalance it with its tail; if T. rex had larger, heavier arms it would have needed an even longer tail to counterbalance the extra weight, and a longer tail would get in the way. We also need to remember that T. rex had a powerful jaw to take down prey and grappling the prey with its arms would be unnecessary. T. rex’s arms appear to have been very muscular and could help it rise from a sleeping position.
Food And Hunting:
T. rex probably ate ceratopsians (mostly Triceratops), hadrosaurs, ankylosaurs, small dinosaurs, and young or sick sauropods. They would also eat dead animals if they came upon some. T. rex would have hunted either by ambushing or chasing its prey. When hunting Triceratops, T. rex would want to avoid being in front of the Triceratops where it could have charged and wounded or killed them. There are a few ways T. rex could have avoided this. 1. T. rex could ambush Triceratops and kill it before it could defend itself. 2. T. rex could intimidate Triceratops by roaring at it and getting it to flee. When this happened T. rex could chase after Triceratops and attack it from behind. 3. T. rex could face off with Triceratops and dodge its charges and attacks and then bite it in the side. Some scientist think T. rex could have ambushed Triceratops and, instead of biting it, would knock it over on its side making Triceratops completely helpless and not able to attack the T. rex. After Triceratops was on its side T. rex would go for the kill. There is also evidence that after killing Triceratops, T. rex would bite its frill and pull off its head to get to the nutritious neck. When hunting hadrosaurs, T. rex didn’t have to worry about getting hurt but had to worry about the hadrosaurs running away because they were faster and could run longer distances. Because of this, T. rex probably ambushed hadrosaurs. While hunting ankylosaurs. T. rex had to be quick and worry about the ankylosaurs’ clubbed tail. They could kill ankylosaurs by dodging their tails and kicking its tender belly or by grabbing their heads and shaking violently. While hunting sauropods, T. rex would have to watch out for their tails and avoid being stomped on. To kill them T. rex would bite their neck and snap the spine or tear chunks out of their sides until they bled to death. T. rex was a strong, formidable predator.
There is some evidence of cannibalism in T. rex. For example, T. rex fossils have been found with other T. rex bite marks on their legs and feet which were hard to reach places if they were just fighting.
There is very little evidence for pack behavior in T. rex. Also if T. rexes were cannibals they might eat their pack members. T. rex mates may have live and hunted together, though.
Young T. rex:
There is evidence that T. rex mothers took good care of there babies. Obviously they were to big to sit on the nest so they would probably line the nest with moss, dirt, rotten wood, and grass just like modern day alligators. Once the young T. rexes could hunt on their own the mother either abandoned them or drove them off. The jaw muscles of juvenile T. rexes weren’t very strong so it would have had to hunt small dinosaurs. In Montana a fossil find of five juveniles T. rexes together suggests pack hunting when they were young. When they got older they would go off to find their own territory.
To conclude, T. rex was the most powerful land predator the world has ever seen. You can see why Tyrannosaurus rex is my favorite dinosaur.