Last month, the tour guide Grover Marquina was traversing the dusty bowl of the Maragua Crater, around 40 miles from the Bolivian capital of Sucre, when he discovered a giant footprint buried underneath rocks and boulders. Measuring some 115 centimeters—or nearly four feet—wide, it is believed to be the largest print from a carnivorous dinosaur to be discovered anywhere in the world. (The previous record setter, found in New Mexico, measured only 110 centimeters.)
According to the Argentine paleontologist Sebastian Apesteguia, who is studying the footprint, the print’s owner was probably an Abelisaurus, a biped dinosaur cousin of the more famous Tyrannosaurus rex. The Abelisaurus roamed South America near the end of the Cretaceous period, between 60 and 80 million years ago. Its characteristics are known only from a partial skull found in the early 1980s near Lake Pelligrini in Argentine Patagonia. Paleontologists José F. Bonaparte and Fernando E. Novas named the genus in 1985 in honor of Roberto Abel, director of Argentina’s Museum of Natural Science.
While nowhere near as famous as its North American theropod cousin, T. rex, Abelisaurus is thought to have been equally imposing. It stood some 40 feet tall on two slender legs, with relatively small, stunted arms and a powerful jaw. It wouldn’t have been alone in the Patagonia region, scientists think, but would have shared its habitat with other carnivorous dinosaurs, including an oversize raptor dubbed the Megaraptor.
Though thousands of Cretaceous-era dinosaur footprints have been discovered in the soft clay near Sucre—which is home to a dinosaur theme park this most recent discovery still stands out. “This print is bigger than any other we have found to date in the area,” Apesteguia told the Guardian. “It is a record in size for carnivorous dinosaurs from the end of the Cretaceous period in South America.”
The discovery of the giant Abelisaurus print also rewrites the timeline of large carnivorous dinosaurs in South America. Scientists have long thought that such enormous creatures roamed the continent as far back as 100 million years ago, but had disappeared by the Late Cretaceous, the last portion of the so-called “Age of the Dinosaurs.” (Most scientists believe dinosaurs went extinct due to the effects of an asteroid that hit Earth 66 million years ago.) The newly discovered footprint, which dates to around 80 million years ago, suggests that the flesh-eating beasts may have stuck around a lot longer than previously believed.