Scientists: Tyrannosaurus walked on its toes
Tyrannosaurus rex is often depicted as a heavy "stomping" animal that puts its foot almost entirely on the ground - like a bear or a human.
But a new study suggests otherwise: T. rex probably walked and ran "on its toes", i.e. transferred most of its weight to its toes, as modern birds do.
The team, led by experts from the College of the Atlantic (USA), studied the legs and feet of four well-preserved skeletons of T. rex. The scientists took precise measurements of the tibia and foot bones and then tested computational models of speed and stride.
The researchers then modelled three ways the foot could have touched the ground:
support on the back of the foot,
midfoot support,
the toes (essentially "toes").
To see which version is more realistic, the results were compared with movement data from humans and ostriches, and also involved fossilised tyrannosaur footprints. In the prints, the deepest areas - where the pressure was greatest - were more often on the fingers. This was one of the arguments in favour of tiptoeing.
According to the authors' calculations, this way of movement could be more favourable for a quick step: it allowed to take more steps in the same time. As a result, the maximum speed of T. rex could be about 20 per cent higher than if it moved "on the full foot".
The researchers estimate that Tyrannosaurus could reach a speed of about 5-11 metres per second (about 18-40 km / h), and the gait itself was closer to the "bird". At the same time for stability of a huge animal, probably helped not only the technique of step, but also the posture: T. rex, according to the authors, moved slightly crouched, making fast, frequent steps, and the legs worked as shock absorbers - it could help to keep balance, including on uneven surfaces.
If the findings are confirmed, it could influence the way Tyrannosaurus is shown in museums, documentaries and films: instead of a heavy, "flat" foot, it has a lighter and more springy foot, with an emphasis on the toes.