- Name: Tyrannosaurus Rex
- Period: Cretaceous
- Diet: Meat
- Size: 12.3m
- Weight: 8.4 - 14 Tons
- Nick: T. Rex, Tyrant Lizard
The Tyrannosaurus Rex, also known as "T. Rex" is a Theropod. Its name "rex" means "King" in Latin. It lived throughout what is now known as western North America, on an island then known as Laramidia. It had one of the largest ranges of hunting grounds of most other tyrannosaurids. They lived about 66 Million Years ago.
Did the T. Rex and Spinosaurus ever meet? In short? No. They lived in different parts of the Cretaceous period, and different regions of the Earth. Unfortunately, they would never have met in real life, unlike how Jurassic Park 3 depicts them fighting.
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Size & Stature
It was by far the largest carnivore in its environment, so it was most likely an Apex Predator and preyed upon hadrosaurs, armored herbivores (including Ankylosaurus), and quite possibly Sauropods like the Apatosaurus. The T. Rex was estimated to have the strongest bite force of all terrestrial animals of its time. Its feeding habits, though, have been a matter of a few subjects of debate. Some say it was more of a scavenger than an active predator, while others say that it was more of an active predator. Both of these were likely true, it likely ate both already dead animals (as in a scavenger), and actively hunted for food.
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Body Design & Health
Their lifespan was likely around 30 years old if they survived that long. The fossil, Sue, was estimated to be 28 years old when it died, and they have found bones from an estimated 14-year-old T. Rex, as well as a 2-year-old T. Rex. The sudden change in growth rates at the end of their growth spurts may have indicated physical maturity; a hypothesis that is supported by the discovery of medullary tissue in the femur of a 16 to 20-year-old fossil from Montana. Medullary tissue is found only in female birds during the time of mating. This indicates that they may have been able to reproduce around that age.
The Tyrannosaurus Rex was historically described as a "living tripod," with the body at a 45-degree angle, and dragging their tail along the ground, like a kangaroo. But in 1970, they realized that this was incorrect. It would have resulted in a dislocation or weakening of several joints, including their hips and the articulation of their head and spinal column. Thankfully, films like Jurassic Park used a more accurate posture to show to the general public! Modern representations of the T. Rex in museums, art, and film show that it was approximately parallel to the ground, with its tail extended to balance the head.
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Speed & Survival
The estimated top speeds of the Tyrannosaurus Rex were around 25 MPH, but were deemed impossible because it would require exceptional leg muscle mass of around 40 to 85% of its total weight! Even moderately fast speeds would require large leg muscles. If their leg mass was less, their max speeds would have been around 11 MPH.
The Tyrannosaurus Rex may have hunted in packs at times, according to fossil evidence. This was because a fossil that has been found in South Dakota found 3 T. Rex skeletons in close proximity to each other. Some of their prey, like Triceratops & Ankylosaurus, had significant defenses, so it would have been more effective for them to hunt in groups. However, this behavior has been criticized, due to not having been peer-reviewed, like normal, as was discussed in a TV interview. The Tarbosaurus and Albertosaurus, on the other hand, likely did hunt in packs (the basis for this hypothesis).
The T. Rex may have been severely affected by parasites and other traumatic injuries by other carnivores. Infections in a Tyrannosaurus Rex were rare, according to Scientific American's website. There has been evidence that the fossil Sue was infected by a parasite, which caused injuries to her lower jaw, which was a somewhat common occurrence amongst the Tyrannosaurus Rex species. The juvenile fossil, Jane, might have been bitten by another juvenile Rex, suggesting that the mighty Tyrannosaurus Rex may have fought each other for food, as well.