How Dinosaurs Moved Down Slippery Slopes

An international team of scientists, consisting of members from the University of Michigan, in the US, the Universidad de Buenos Aires, in Argentina, and the Iziko South African Museum, in Cape Town, South Africa, has recently revealed new clues of how dinosaurs moved down slopes. Apparently, in spite of their massive size, the animals were able to control their motion and make on-the-fly adjustments to their strides, so as to minimize the risk of falling down. If a massive dinosaur tilted over, chances were it wouldn't have been able to get back up again, e! Science News reports.

In the new investigation, published online in the October 6 issue of the open-access journal PLoS ONE, the team reveals that the way early dinosaurs made stride adjustments to their paces may yield some further insight into the later evolution of the creatures.

“Tracks and trackways bring animals to life in a way that their bones cannot, by providing a brief but vibrant record of a living, breathing animal as it moved through its environment. While fossilized bones can provide a wealth of information about extinct animals' anatomy and physiology, inferences about their locomotion and behavior are necessarily indirect,” University of Michigan (UM) Department of Geological Sciences Assistant Professor Jeffrey Wilson, who is also an assistant curator in the Museum of Paleontology, explains.

The site the team analyzed is located in the African country of Lesotho, and is known as the Moyeni tracksite. It contains in excess of 250 footprints, left behind by animals living about 200 million years ago, at the beginning of the Jurassic Period. Paul Ellenberger, a French paleontologist, discovered the site back in the 1960s, and described it over the next decade. In the past 30 to 40 years, little serious academic research was conducted in the area, apart from the new investigation.

Now, using a 3D surface scanner, in addition to traditional mapping techniques, the team members managed to obtain a clear, high-resolution map of the trackway surface, which aided them in their research considerably. In the past, the area included a wet riverbed, a sloping bank, and a flat, upper surface, which presented the dinosaurs with a fairly difficult terrain to navigate. The meat-eating variety, the team determined, walked on two legs at all times, gripping the slippery soil with their claws. Conversely, the plant-eaters walked on all fours on slippery and wet terrain, and on only two feet on the flat surfaces.

The analysis could also hint at something terribly important, Wilson says. “One idea about the origins of flight is that the progenitors of birds learned to fly by flapping their wings while climbing inclined surfaces. In that scenario, the ability to grip a surface with claws is important,” he concludes.