A Daspletosaurus (centre left), a close relative of T. rex that shared its way of moving, chases down a Spinops with a Coronasaurus (right) looking on in a handout ilustration. (Julius Csotonyi photo)

Not a sprint star: Research says T. rex was built for distance, not speed

T. rex’s long legs would have made that a very efficient 20 km/h, a pace that could be kept up for quite a while

Tyrannosaurus rex, one of the most feared predators in the Age of Dinosaurs, may have been built for endurance, not speed.

A paper published Wednesday takes recent research on how mammals move and applies it to dinosaurs. Its conclusions support theories that the massive meat-eaters hunted in packs and opens a window into the ecology of the ancient forests they roamed.

“We’re trying to figure out how much energy is going into and flowing through paleo ecosystems,” said Hans Larsson of Montreal’s McGill University, one of the paper’s co-authors.

“If we can’t get an estimate for what it takes to feed the apex predators, then we have no chance of estimating anything else.”

To figure out how much T. rex needed to eat, the scientists first had to figure out how it moved, including how fast it could run.

In the past, that’s been done using a formula based on hip height.

“That, coupled with body mass, can tell us a lot about speed,” said Larsson.

The problem is that an animal’s speed comes from many factors — the relative length of certain leg bones; whether it runs on its toes or its heels; its size.

Consider the elephant. Its hip height is lengthy, but a gazelle can run rings around it.

“Lots of other things come into play,” Larsson said.

“What we wanted to do was recalibrate … dinosaur speed using some really cool new papers that have come out using mammals, especially really large mammals.”

Larsson applied those papers to dinosaurs, bringing body mass into the calculation.

Earlier papers proposed T. rex could achieve speeds of up to 70 km/h — a lightning pace for an animal that would have weighed more than 10 tonnes. Larsson suggests its top end would have been closer to 20 km/h.

But, he adds, T. rex’s long legs would have made that a very efficient 20 km/h, a pace that could be kept up for quite a while.

Larsson asked what that could mean.

“If this were their mode of hunting, being able to go much greater distances at a pretty good clip, what kind of lifestyle would that be? The animals that do this today are ones, like wolves, that hunt in packs.”

Near Red Deer, Alta., a group of many large, meat-eating dinosaur fossils appear to be from members of a single flock.

“It’s pretty good evidence,” said Larsson.

Understanding how the top predator in the forests of the Cretaceous era moved and hunted allows scientists to also ask better questions about that ancient ecosystem.

How much food would T. rex have needed to move that huge body at that pace? How much prey would have had to have been available? What would that prey have needed to eat?

Answering those questions will have direct benefits for modern biology, Larsson said.

“Some of the fundamental questions on current ecosystems are still not there. In most cases, we don’t even know what the food web is.”

Rebuilding an ancient food web from sketchy fossil records could give science a road map to find its way through the incredible complexity of a living forest, he said.

“We can start off with a paleo ecosystem and start developing ideas that can be used to begin tackling these questions in living ecosystems. The data become far simpler.”

Bob Weber, The Canadian Press

Like us on Facebook and follow us on Twitter.

Want to support local journalism during the pandemic? Make a donation here.

Science

Get local stories you won't find anywhere else right to your inbox.
Sign up here

Just Posted

Boundary freshet 2020: At least 189 properties ordered to evacuate as of June 1

Real-time gauges on the West Kettle, Kettle and Granby rivers suggested Monday water near peak

City of Rossland opens playground structures to public

Residents are reminded to drive cautiously in school zones as children head back to school this week

UPDATED: 189 homes in Grand Forks area given evacuation orders

Homes are in the Nursery, Grand Forks Airport, Gilpin Rd., Johnson Flats and Granby Rd. areas

Mercer Celgar announces 30 days of downtime at Castlegar mill in July

Sawlog stumpage charges on pulpwood and complex stumpage rules some reasons for downtime

Flood warning issued for Boundary as Kettle River expected to rise to 20-year return level

RDKB: This amounts to a high flood risk for low-lying properties in the region

VIDEO: A Vancouver Island black bear takes weekend nap in eagle tree

Videos captured by Terry Eissfeldt shows the bear arriving Saturday night and sleeping in on Sunday

George Floyd asphyxiated by sustained pressure: family autopsy

Death sparked a wave of protests across the U.S. and abroad

B.C. Hockey League prepping for 2020-21

League reviewing different scenarios and start times in compliance with provincial regulations

COVID-19: B.C. commercial landlords can’t evict if they decline rent assistance

Emergency order ‘incentive’ for federal program, Carole James says

Investigators probe death of CN employee at Surrey rail yard

Transportation Safety Board is investigating an ‘occurrence that took place during switching operations’

Trans Mountain starts B.C. leg of pipeline twinning project

Mostly finished in Alberta, Burnaby terminal expanding

NDP getting COVID-19 wage subsidy ‘indirectly,’ B.C. Liberal leader says

Andrew Wilkinson says he’s heard no concerns from public

Most Read