An extraordinary discovery of near-identical dinosaur tracks across two continents has shed light on the dramatic tectonic shifts that began 140 million years ago. Over 260 dinosaur footprints, found in Brazil and Cameroon, date back 120 million years and reveal that, at that time, dinosaurs could still walk freely between what are now separate continents.
During the time that South America and Africa were a part of the larger landmass known as Gondwana, these footprints were left in old river and lake beds. Theropods, sauropods, and ornithischians were among the dinosaurs that formerly wandered freely over the thin geological bridge that connected northeastern Brazil to the modern-day coast of Cameroon. Due to the 6,000 kilometers (3,700 miles) of ocean that separates the continents, these creatures are no longer able to travel between them.
According to Louis Jacobs, a paleontologist from Southern Methodist University, the two continents were continuous along a narrow stretch, allowing the animals to cross freely. This connection started to disappear 140 million years ago when tectonic forces began ripping Africa and South America apart. The resulting seismic activity split the land and gradually formed the South Atlantic Ocean.
The evidence of this tectonic split can still be seen today in the form of half-graben basins in both Africa and South America, which hold sediments from ancient rivers and lakes. These areas also contain fossilized pollen and the remarkable dinosaur prints, which help tell the story of Gondwana’s breakup. This discovery stitches together a prehistoric journey, providing clues to how dinosaurs lived on a connected landmass, long before the continents became separated by vast oceans.