North American paleontologists concluded that the evolution of larger dinosaurs favored energy savings, which made hunting more efficient.
A study by a group of American universities revealed that, contrary to popular belief, Tyrannosaurus Rex was not a fast runner. That’s because their legs have evolved to help them conserve energy and travel long distances while looking for prey.
The study, published in the scientific journal PLOS ONE, states that the body of these animals was optimized for walking and, even if they ran, they could not reach very high speeds. “Those adaptations may also be for endurance and efficiency. It may be about being a marathoner rather than a sprinter,” said Thomas Holtz, a researcher and geologist at the University of Maryland, in a statement.
To conduct the research, the team collected data about limb proportions, body mass, size ratio, and gait of more than 70 species of theropod dinosaurs, including the T-Rex. After that, they analyzed the top speed of each of them, as well as the amount of energy they spent while traveling at lower speeds.
Based on the results, they realized that for small and medium-sized dinosaurs, longer legs were associated with faster running. However, for the larger dinosaur species, which weighed more than a ton, the top speed was limited by body size.
The authors suggest that, although speed was a great advantage for dinosaurs to escape from predators, larger theropods were also the most efficient at hunting. “That’s actually a very beneficial savings, because predators tend to spend a great deal of their time foraging, searching for prey,” explained Holtz. “If you are burning less fuel during the foraging part of the day, that’s an energy savings that dinosaurs with shorter leg forms didn’t get.”