Simulation of limb movement based on fossil tracks shows that giant long-necked dinosaurs walked most similarly to modern hippos.
Simulation of a giant long-necked dinosaur. (Photo: Elena Duvernay).
Sauropod dinosaurs were the largest creatures to ever walk the Earth, including some species of long-necked dinosaurs (Diplodocidae) that could reach lengths of over 30 meters and weigh as much as 14 African bush elephants.
“People often assume that Sauropods walked like modern elephants, but that is not the case,” said paleontologist Jens Lallensack from Liverpool John Moores University in a new study published in the journal Current Biology on March 2.
Elephants have a “side-to-side” gait, meaning that the two limbs on one side of the body step forward alternately, followed by the limbs on the opposite side. For example, the right front leg steps forward, followed by the right hind leg, then the left front leg, and finally the left hind leg.
Video: Peter Falkingham)
However, by simulating the limb movement of Sauropods based on fossil tracks, Lallensack and colleagues found that these giant dinosaurs exhibited a “cross gait,” with each step of the front limb followed by the opposite hind limb.
“Sauropods actually walked in the opposite manner to elephants. We believe this difference is due to their much larger body size,” the lead author of the study added.
The cross gait allows these massive creatures, which could weigh over 50 tons, to maintain better balance by ensuring that at least one limb is always on the ground on each side. Currently, the animal that most closely resembles the gait of Sauropods is the hippo, a species also known for its heavy body and wide limb spacing.
Lallensack’s team analyzed a series of Cretaceous fossil tracks of Sauropods at three different sites in Arkansas and found that their footprints were spaced further apart than any modern animal.
“If they had a gait like elephants, the bodies of Sauropods would wobble significantly. For truly large and heavy creatures, that instability would put stress on the muscles and bones. This is a major issue,” Lallensack emphasized.
