New dinosaur tracks found in U.S. state

Researchers at the University of Arkansas are studying a new field of fossilized dinosaur tracks, including one set that appears to be from a large three-toed predator, the university said on October 05.

The tracks were found on private land in southwest Arkansas and provide a window into the life forms that roamed the area as long as 120 million years ago during the Early Cretaceous period.

“The quality of the tracks and the length of the track ways make this an important site,” said Stephen K. Boss, who led the project.

The research effort is funded by a grant from the National Science Foundation.

Based on the rock in which the footprints were found, researchers have a good idea of what the climate would have been like, Boss said.

“Picture an environment much like that of the shores of the Persian Gulf today. The air temperature was hot. The water was shallow and very salty,” Boss said. “It was a harsh environment. We’re not sure what the animals were doing here, but clearly they were here in some abundance.”

Some of the tracks in the field have not been documented before in Arkansas. The researchers’ work will expand knowledge about dinosaurs that roamed the area and the climate during the period.

The tracks from the three-toed dinosaur are about 2 feet (0.6 meters) long by 1 foot (0.3 meter) wide and likely are from Acrocanthosaurus atokensis, one of the largest predators ever known. There are also prints from sauropods, large, long-necked plant-eating dinosaurs. Other sauropod tracks have been found in the state, including at a site near Nashville, also in the state’s southwest.

“Through tracks, we can learn all sorts things about dinosaur biomechanics and behaviour,” said University of Kansas researcher Brian Platt, who is taking part in the program. “Dinosaur bones can be dragged away by animals or swept out to sea. But we know that about 120 million years ago, dinosaurs walked right through here.”

The grant from the National Science Foundation enabled a team of researchers to spend two weeks studying the site. They used traditional tools, including hammers, chisels and brooms, but also cutting-edge technology to record images, take measurements and map the site.

Rock samples from the site can also shed light on the conditions under which the dinosaurs lived.

“Because we see footprints here, we know that this surface was at one time exposed to the elements,” said Celina Suarez, a postdoctoral researcher at Boise State University who will be joining the faculty at the University of Arkansas in the fall of 2012.

Researchers can calculate how much rain fell and how much moisture evaporated. Using data from this site and others, scientists can learn more about the climate in general and work to predict the planet’s future climate.

“This site will add to the knowledge of both the animals and climate of the Early Cretaceous,” Boss said. “Scientists will be studying these data for many years.”