Tyrannosaurus Rex – King of the Dinosaurs?

Tyrannosaurus Rex was a large carnivorous dinosaur that lived during the late Cretaceous period from approximately 67 to 65.5 million years ago. It is the largest, most wide-ranging and best known of the Tyrannosauridae family, reaching a length of up to 42 feet and an estimated weight of 15,000lbs. Tyrannosaurus Rex is recognized as one of the last terrestrial dinosaurs prior the mass extinction that occurred at the end of the cretaceous period.

"Jane" - a well-known specimen.

Tyrannosaurus Rex is best recognized by its extremely long head (up to 5 feet in length), long, powerful legs and extremely small two-fingered forelimbs. It was originally believed that bipedal dinosaurs such as T-Rex walked and stood nearly upright with their tails dragging on the ground. In the 1970’s paleontologists began to realize that such a posture would be impossible for these animals, and it has now been determined that T-Rex walked with its body nearly parallel to the ground with its massive tail helping to balance the weight of its heavy head.

Early 20th century depiction of T. Rex walking upright.

T-Rex’s life habits have long been a subject of debate. Although likely an apex predator, there are still some who believe that Tyrannosaurus was primarily a scavenger. These beliefs stem from the fact that T-Rex, with so much weight at opposite ends of its body, could not have been very agile and may have required several seconds to change direction. However, it was still likely fast enough to catch large prey, with its top speed estimated to be between 25 and 45mph. Additionally, T-Rex’s tiny forelimbs, once thought to be useless, are now believed to have been very strong and likely to hold prey down while feeding.

Tyrannosaurus Rex fossils have been found throughout what is now western North America. The T-Rex’s size, fearsome appearance and relatively large amount of remains have led it to become perhaps the world’s best known dinosaur, and a subject of many fictitious books and movies.