A new method of analyzing dinosaur footprints has revealed that sauropods had a gait unlike any creature today.
Previous research showed that elephants walked by taking two steps on one side, then two on the other. Because they were so large, many paleontologists assumed that giant dinosaurs walked similarly. In this new study, researchers found that this was not the case.
Previous research focusing on dinosaur footprints convinced the researchers that the traditional method of footprint analysis needs to give a complete picture of how a particular dinosaur walked. They also noted that due to the enormous size of gigantic dinosaurs, such as sauropods, walking like an elephant would have required a lot of energy to avoid toppling over.
So the researchers created a new method for studying pathways that accounts for variations in tracks and timing as an animal moves forward. They analyzed footprint pathways for three sauropods by measuring the distance between footprints and paying attention to whether the feet were made from the front or back and whether they were left or right. They then calculated how the limb phases matched the tracks they measured, which allowed them to predict gait.
The researchers tested their new approach by using this method to measure the tracks of several modern animal species, including elephants. They tried their method on the tracks of modern quadrupeds, including three dogs, two horses, a camel, an elephant, a red fox, and a raccoon. They then used it to study tracks left by several sauropods, as they believed it better represented the gait of a particular animal.
With this method, they found that a front foot touched the ground just before a hind foot on the opposite side was lifted. This gait suggests that the giant creatures did not sway as they walked, thus conserving energy.
Lallensack says the sauropod tracks do not match any modern animals they analyzed. Instead, they had a gait resembling a horse’s trot, but instead of landing simultaneously, the front foot touched just in front of the hind foot on the opposite side.
“Sauropods were doing the opposite of elephants,” Lallensack says.
This diagonal gait could have kept the giants balanced by always having at least one foot on each side. The only animal alive today with speed somewhat close to that of sauropods is the hippopotamus, a heavy animal with wide legs.