The fossil bones the remarkable track matched were found just 150 miles (250 kilometers) away, in the same red rocks.
"Anatomically, the record of (intact) and complete (hind feet) is really scarce in titanosaurs," Riga reported. In fact, of the 65 species of titanosaurs known worldwide, only three have intact fossils of their feet, he writes.
That's not to say that the bones belonged to the same individual that made the tracks -- they're not only far apart in space, but also in time. But they do belong to a similar titanosaur.
"Not all tracks can be matched to specific skeletons because foot structures do not vary that much in some dinosaur groups," Lucas said. "Relatively few dinosaur tracks have been matched with certainty to a dinosaur (type). Sometimes, the bones from one rock formation are claimed to represent the trackmaker of tracks in the same formation, but even this is not often a certain link."
Among the other things revealed by the trackways are just how fast some of the titanosaurs walked across the muddy ground they encountered in the late Cretaceous.
By looking at fine details in the fossilized mud, Riga and his team calculated the titanosaurs strolled at about 3 miles per hour (4.8 kph).
The tracks of three different types of small, three-toed theropods dinosaurs were also found in the same mud. The two-legged, usually carnivorous, dinosaurs were relatively small, Riga reports.
But unlike the titanosaur tracks, the researchers could not glean enough information from these tracks to narrow down to which group of theropods they belonged.