Therapists often ate meat and walked on two legs. Spanish researchers are now using footprints to calculate how fast these ancient lizards run.
Some dinosaurs can reach speeds of up to 45 kilometers per hour. This is what the ancient researchers concluded from their analysis of the footprints in the northern Spanish region of La Rioja. Traces come from theropods, mainly carnivorous dinosaurs, the most famous representatives of which are the dinosaur Rex species.
Decades ago, researchers discovered hundreds of dinosaur footprints near the city of Izia. A team led by Pablo Navarro-Lorbase from the University of Rioja in Logrono has now analyzed two series of prints, each containing about half a dozen tracks. The individual prints are about 30 centimeters long and are about the same size as the researchers thought they came from.
Up to 45 kilometers per hour
In principle, the speed of extinct animals can be determined in two ways, the authors write: by anatomical biomechanical models or by the analysis of footprints. For this purpose, the waist height is calculated from the length of a log and set in relation to the step length.
The distance between the separate tracks in the two series prints is approximately 2.65 and 2.80 m, so the sequence of steps measures twice as long. The waist height of the animals was approximately 1.30 and 1.15 m, respectively.
From this, the researchers estimate that the average speed of one animal is 23 to 37 kilometers per hour and that of another is 32 to 45 kilometers per hour. “These speeds have so far been determined by trace analysis in dinosaurs,” they write in the journal Scientific Reports.
In comparison: the leopard is the fastest mammal in the country and can reach speeds of up to 120 kilometers per hour. The largest rats, the ostriches, can run at speeds of up to 70 km / h.
Tyrannosaurus rex was slow
However, the record holder for the therapists tested by Trace Analysis was a model analyzed in the US state of Utah. According to another research team earlier this year, it came in at a speed of nearly 50 kilometers per hour.
Another group determined even higher speeds using biomechanical models: Thus, researchers at the British Royal Society’s Proceedings B “in 2007 reported that the composcondas, only one meter smaller, reached a theoretical speed of 65 kilometers per hour. . According to this analysis, the Tyrannosaurus Rex ran up to 29 kilometers.
Spanish researchers do not know what kind of dinosaurs left their traces in Rioja in the early Cretaceous 150 to 100 million years ago. But they write that they must have been very active, medium-sized theropods.