Giant long-necked dinosaurs walked with a different Gait from that of any living animal, according to a new method for learning an animal’s stride pattern from its footprints. Unlike elephants, which take two steps on one side, then two steps on the other, sauropods have a diagonal Gait, with each step of a front leg closely followed by the hind leg on the opposite side.
This would have allowed the 50-plus-tonne animals to keep their wide frames in balance, says Jens Lallensack at Liverpool John Moores University in the UK. Lallensack and Peter Falkingham, also at Liverpool John Moores University, suspected that previous studies on footprints alone weren’t telling the whole story.
The sauropod tracks didn’t match the modern animals they analyzed, says Lallensack. Instead, they showed a Gait that somewhat resembled a horse’s trot, but instead of landing at the same time, the front foot touches down just before the hindfoot on the opposite side. This diagonal would have stabilized the giants by ensuring they always had at least one foot on the ground on each side. The only animal alive today with a Gait somewhat close to that of the sauropods is the hippopotamus, a heavy animal with widely set legs, but it has more of a trotting Gait.