Watch your step

T. rexes were the original slow walkers — watch

You may think you know how dinosaurs moved from pop culture, but a new study suggests the mighty T. rex may have moved at a more leisurely walking speed than you imagined.

P. Bijlert, et al. ROYAL SOCIETY OPEN SCIENCE (2021)

In a study published Wednesday, researchers from the Netherlands shared their findings on the likely walking speed of the T. rex. They arrived at their conclusion through 3D reconstruction.

P. Bijlert, et al. ROYAL SOCIETY OPEN SCIENCE (2021)

The researchers used Trix, a nearly complete T. rex fossil excavated by the Naturalis Biodiversity Center in the Netherlands, as the basis for their model.

P. Bijlert, et al. ROYAL SOCIETY OPEN SCIENCE (2021)

To arrive at their proposed walking speed, the researchers didn’t focus on Trix’s legs — they examined its tail.

P. Bijlert, et al. ROYAL SOCIETY OPEN SCIENCE (2021)

T. rex tails were suspended by ligaments in such a way that it didn’t cost the dinos any extra energy to hold them up. However, they bounced with each step, making them important to the researchers.

Corey Ford/Stocktrek Images/Stocktrek Images/Getty Images

Animals tend to walk at the rhythm that uses the least energy. For T. rexes, that meant matching their gait to the swaying of their tails.

P. Bijlert, et al. ROYAL SOCIETY OPEN SCIENCE (2021)

Using a 3D reconstruction, the team estimated the frequency at which T. rex tails would have naturally bounced up and down. To minimize energy use, T. rexes would have matched their steps to this rhythm.

McCrea, et al. PLOS ONE (2014)

To calculate a walking speed, the researchers combined the tail’s rhythm with an estimate of step length derived from an intact fossil of another T. rex’s footprint trail.

The team came up with a walking speed of 2.86 miles per hour. That’s much slower than previous estimates based only on T. rex leg length.

P. Bijlert, et al. ROYAL SOCIETY OPEN SCIENCE (2021)

guenterguni/E+/Getty Images

The slower walking speed proposed by the study is in range of what’s common for animals from humans to elephants, according to the researchers.

P. Bijlert, et al. ROYAL SOCIETY OPEN SCIENCE (2021)

Aside from giving us a fuller picture of the prehistoric world, studying the movement of ancient animals can help scientists understand how they evolved into the animals of today.

Read more stories on animals here.

MARK GARLICK/SCIENCE PHOTO LIBRARY/Science Photo Library/Getty Images

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