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Tyrannosaurus Rex: Quick Facts

Larry Slawson received his master's degree at UNC Charlotte. He specializes in Russian and Ukrainian history.

Quick facts about the terrifying T-Rex

Quick facts about the terrifying T-Rex

Tyrannosaurus Rex: Quick Facts

  • Species: Tyrannosaurus Rex (“T. Rex”)
  • Discovery: 1905 (Henry Fairfield Osborn)
  • Regional Origins: Western North America; Possibly Asia
  • Measurements: 13–14 Feet Tall (4 Meters); 40 Feet Long (12.3 Meters)
  • Weight: Nine Tons (8,000+ Kilograms)
  • Speed (Estimated): 10 to 25 m.p.h. (Possibly faster, given advances in recent research)
  • Lifespan: 28 Years
  • Feeding Habits: Carnivore; Predator and possible scavenger
  • Period: Cretaceous Period (Maastrichtian Era); 68–66 Million Years Ago
  • Number of Fossils Found: 50+ Specimens (Most famous, "Sue")
  • Skin/Appearance: Disputed (Scientists remain divided over whether or not T-Rex possessed scales, feathers, or fluff/fuzz). It is also unclear what color Tyrannosaurus's skin was. Scientists can only speculate on this matter at this time.
The deadly Tyrannosaurus Rex.

The deadly Tyrannosaurus Rex.

Scientific Classification

  • Kingdom: Animalia
  • Phylum: Chordata
  • Clade: Dinosauria
  • Order: Saurischia
  • Suborder: Theropoda
  • Family: Tyrannosauridae
  • Subfamily: Tyrannosaurinae
  • Genus: Tyrannosaurus
Size comparison between T-Rex and adult human.

Size comparison between T-Rex and adult human.

About Tyrannosaurus Rex

Tyrannosaurus Rex was a bipedal carnivore (meaning it walked on two legs) that existed 68 to 66 million years ago during the Cretaceous Period. The T-Rex was one of the largest known (land-based) carnivores/predators to have existed across time and history.

The name “Tyrannosaurus Rex” comes from a mix of Greek and Latin words. “Tyrannosaurus” (in Greek) refers to “tyrant lizard.” “Rex” (in Latin) means “king.” Tyrannosaurus measured nearly forty feet long and stood upwards of thirteen to fourteen feet tall. This length proved vital for T-Rex as it provided stability for his (or her) large and heavy head, which measured nearly 4–5 feet long.

T-Rex also possessed the largest known set of teeth amongst dinosaur species, with the largest one measuring nearly 12 inches long (approximately 30 centimeters), and the rest measuring in at an impressive 8 inches. It is estimated that the T-Rex possessed up to 60 of these razor-sharp teeth, which allowed Tyrannosaurus to subdue its prey with ease.

Many scientists continue to debate whether T-Rex was a scavenger or a predator. However, the presence of these large teeth, combined with T-Rex’s forward-facing eyes and head features, along with its flexible neck, provide strong evidence that he was, indeed, predatory in his hunting habits. It is also believed by many scientists that T-Rex’s primary senses were centered around smell and vision, allowing him to easily locate nearby prey (a key characteristic of many modern animal species [predators] today).

In 1905, T-Rex was officially identified and named by Henry Fairfield Osborn (a paleontologist with the American Museum of Natural History).

T-Rex Arm Length

Scientists continue to debate what purpose/role T-Rex's short arms played in its day-to-day life. According to palaeobiologist, Sara Burch, T-Rex likely used these arms "for grasping and stabilizing objects" ( It is also possible that T-Rex used its arms for "display" purposes as well; either for competition with other males, or for attracting mates ( Some scientists even believe it is possible that T-Rex's arms were covered in feathers as well. Although it is unclear whether or not T-Rex possessed feathers, their presence (if confirmed) would provide substantial credence to the possible link between dinosaurs and birds. However, additional research is needed on the matter before conclusions can be made with certainty.


T-Rex has appeared in multiple series and movies across the twentieth and twenty-first centuries. These include:

Jurassic Park, Jurassic Park 2, Jurassic Park 3, Jurassic World, Night at the Museum, Land of the Lost, Dinosaurs, and Toy Story to name only a few. These movies, along with popular portrayals, demonstrate the T-Rex's overwhelming popularity and generally support the claim that T-Rex remains one of the most recognizable dinosaurs of all time.

Similar Species

Members of the Tyrannosauroidea family included: Albertosaurus, Eotyrannus, Gorgosaurus, and Alioramus. Each of these species possessed long, powerful bodies, with large heads, bipedal movement, and short, tiny arms.

Prey of the T-Rex

It is unknown what T-Rex regularly fed on. However, many scientists believe that Triceratops and Edmontosaurus both served as prey to T-Rex. It is also believed that Tyrannosaurus may have fed on other T-Rex, as large teeth marks have been discovered on many T-Rex specimens.

Karl Bates and Peter Falkingham (in 2012) estimate that the T-Rex may have had “the most powerful bite of any terrestrial animal that has ever lived” (Wikipedia). According to some estimates, “the dinosaur’s bite could exert up to 12,814 pounds-force” ( According to the Natural History Museum, it is believed that T-Rex's bit "was around 3 times as powerful than that of a lion" ( Scientists, such as William Abler, have also hypothesized that T-Rex possessed teeth that contained infectious bacteria. Similar to some modern reptiles, this bacteria would have been harmful to its prey (Wikipedia).

Pack Behavior

It is unknown (and highly debated) whether T-Rex hunted its prey alone or with packs. For many years, scientists have hypothesized that T-Rex hunted alone due to the large number of isolated skeletal remains that have been discovered. However, in more recent years, many scientists have shifted in this stance; incorporating a viewpoint that gives credence to T-Rex's ability (both physically and mentally) to function within a group setting. Scientists base this hypothesis on evidence discovered in both the Gobi Desert and South Dakota. In both areas, numerous T-Rex (and Tyrannosaurid) remains were discovered in close proximity to one another, indicating a possibility that T-Rex hunted in groups, rather than alone. Revelations such as these are monumental in the science community, as they indicate that T-Rex may have been smarter and more intelligent than previously believed (

Other scientists continue to remain skeptical about T-Rex' pack behavior. Given that "some Tyrannosaurus fossils show bite marks from other tyrannosaurs," many scientists argue that the close proximity of fossils may have resulted, instead, from territorial fights, "whether over food or mates" (

Popular depiction of T Rex

Popular depiction of T Rex

Final Thoughts

Tyrannosaurus Rex was one of the most powerful dinosaurs (and predators) to have ever existed. Although much is known about T-Rex and its characteristics/traits, much can still be learned about this amazing dinosaur as technological advances, research, and additional discoveries are made in the near future. Only time will tell what exciting new facts can be discovered by scientists and researchers.

In the meantime, we can continue to follow Hollywood, authors, and artists, alike, in their popular portrayals of T-Rex. Whether these portrayals prove factual or not, remains to be seen.

Works Cited

  • Castro, Joseph. "Tyrannosaurus Rex: Facts About T. Rex, King of the Dinosaurs." LiveScience. October 17, 2017. Accessed June 04, 2018.
  • Collins, Nick. "Tyrannosaurus Rex 'hunted in Packs'." The Telegraph. June 22, 2011. Accessed June 12, 2018.
  • Gallagher, Brian. "T-Rex Revealed in Jurassic World Viral Video." MovieWeb. February 26, 2016. Accessed June 04, 2018.
  • "Palaeontology: The Truth about T. Rex." Nature News. Accessed June 15, 2018.
  • Pepper, Darren. "Tyrannosaurus." Allosaurus. Accessed June 12, 2018.
  • "T-Rex Wallpapers." Fun Animals Wiki, Videos, Pictures, Stories. Accessed June 04, 2018.
  • "Tyrannosaurus." Natural History Museum. Accessed June 15, 2018.
  • "Tyrannosaurus." Wikipedia. June 02, 2018. Accessed June 04, 2018.

This content is accurate and true to the best of the author’s knowledge and is not meant to substitute for formal and individualized advice from a qualified professional.

© 2018 Larry Slawson


Larry Slawson (author) from North Carolina on May 08, 2019:

Totally agree Gavin. Its crazy that a predator this big once roamed the Earth haha.

gavin on May 08, 2019:

coolest dinosaur ever

Larry Slawson (author) from North Carolina on June 12, 2018:

@Eric That's a great idea! I am going to definitely do that!

@John and @Poppy Haha, definitely true. He is quite scary. Even just the skeletal remains are terrifying to behold. I can only imagine how scary the T-Rex was in person.

Poppy from Enoshima, Japan on June 09, 2018:

Despite how cool and breathtaking it would be to see one of these guys in real life, I'm glad they're extinct. Very interesting read; thank you.

John M McNally on June 09, 2018:

Hi Larry, packed with interesting facts. I particularly liked the quick facts at the beginning. I guess I thought I knew a bit about the T Rex but soon realized that I didn't. Now I do. You wouldn't want that bad boy running you down.

Eric Dierker from Spring Valley, CA. U.S.A. on June 05, 2018:

Larry do not get me started. I am a research freak and it is rubbing off on my son. I do not think we go a day without a reference book or research on the net.

Your style here really works for us. It might be too hard but a lay out graph of the sizes like a ruler type deal with, on the head legs or whatever and a whale by comparison. Kind of like a cross for a visual learner and a kinesthetic. (that may make no sense)

Sorry too much from me.

But I will study this for method/delivery of "things".

Larry Slawson (author) from North Carolina on June 05, 2018:

Thank you Faith!

@Eric I’m glad you enjoyed haha. I thought that I might try something new with this article. Haven’t dabbled much with science related articles before. But I plan to do some more like this, I think. Do you have any suggestions on items that I could add to make it better?

Eric Dierker from Spring Valley, CA. U.S.A. on June 04, 2018:

You really excellent here. Thank you. I have not decided whether to read this with my son for our daily 30 minutes or to keep it to myself so I can be smarter ;-)

Why did I think the one from very south America was not as badass but bigger? I think Alio.

Faith-Hope-Love on June 04, 2018:

Interesting piece, Good but short Read.