70-mn-year-old footprints shed new light on dinosaurs

Geologist Greg Browne of GNS Science said the footprints shed considerable light on how fast dinos moved, how big they were as well as how soft the sediment was when they moved through the area. Browne made the discovery while investigating the properties of the rock and sediment formations in the northwest Nelson region of the country. There are six locations over an area stretching about 10 km where footprints appear. At one location there are up to 20 footprints left by dinosaurs.

Browne carefully considered all the possible geological and biological explanations for the features in the rock and was able to rule them out one-by-one. His investigation included comparisons with dinosaur footprints in similar aged rocks in other parts of the world. He concluded that the most plausible explanation was the markings were made by sauropods - large herbivorous dinosaurs with long necks and tails and pillar-like legs. “What makes this discovery special is the unique preservation of the footprints in an environment where they could easily have been destroyed by waves, tides, or wind,” Browne said.

The depressions are roughly circular in plan view, with the largest about 60 cm in diameter, said a release by GNS Science, a research institute. Most are smaller - typically between 10 and 20 cm in diameter and were probably formed by dinosaurs between two metres and six metres long, weighing several tonnes. These findings are slated for publication in the New Zealand Journal of Geology and Geophysics.