When Tyrannosaurus rex was first discovered more than a century ago, there was a lot about it that scientists didn’t know yet. In the years since, a lot of these mysteries have been solved– however, the public’s idea of these ferocious fossils sometimes lags behind.

In the early 1900s, scientists guessed that T. rex had a posture like a kangaroo– they stood on two legs and had tiny front limbs, so paleontologists thought that maybe T. rex dragged its long tail on the ground and used it like a tripod in order to stand tall. This picture of T. rex was immortalized in lots of scientific art, some of which is still hanging in museums today. But this idea is outdated– today, scientists are pretty sure that T. rex had a more crouched posture, with its tail held out straight behind it for balance. This posture makes more sense based on the information researchers have about how the dinosaur’s muscles would have attached and how it would have been able to move. So the next time you see a picture of a T. rex standing up super straight, remember that it’s not quite right!


Illustration by William D. Matthew, 1905.