A groundbreaking discovery by an international team of researchers, led by SMU paleontologist Louis L. Jacobs, has unveiled matching sets of Early Cretaceous dinosaur footprints on two different continents. Over 260 footprints were discovered in Brazil and Cameroon, offering a fascinating glimpse into a time when dinosaurs roamed freely across what are now separate landmasses.
These ancient footprints, formed in mud and silt along rivers and lakes, were found more than 3,700 miles (6,000 kilometers) apart. Dinosaurs made these tracks around 120 million years ago on a single supercontinent called Gondwana, which later separated from the larger landmass of Pangea. This discovery suggests that land-dwelling dinosaurs could move freely between South America and Africa before the continents split apart.
“We determined that in terms of age, these footprints were similar,” said Jacobs. “In their geological and plate tectonic contexts, they were also similar. In terms of their shapes, they are almost identical.” This finding is significant because it provides clear evidence of a once-connected land bridge that allowed dinosaurs to traverse between what are now Brazil and Cameroon.
A Narrow Passage Between Continents
One of the last geological connections between Africa and South America was a narrow land strip where northeastern Brazil met the coast of what is now Cameroon, along the Gulf of Guinea. “The two continents were continuous along that narrow stretch, so that animals on either side of that connection could potentially move across it,” Jacobs explained. This narrow corridor provided a pathway for dinosaurs to migrate and interact across continents before the Atlantic Ocean formed.
Most of the footprints discovered belong to three-toed theropod dinosaurs, known for being carnivorous and agile hunters. Some footprints also appear to have been made by larger herbivorous dinosaurs, such as sauropods or ornithischians, according to Diana P. Vineyard, a research associate at SMU and co-author of the study.
Other notable co-authors of the study include Lawrence J. Flynn from Harvard University, Christopher R. Scotese from Northwestern University, and Ismar de Souza Carvalho from the Universidade Federal do Rio de Janeiro and Centro de Geociências. Their findings were published by the New Mexico Museum of Natural History & Science in a tribute to the late paleontologist Martin Lockley, who dedicated much of his career to studying dinosaur tracks and footprints.
A Geological Tale of Two Continents
Africa and South America began to drift apart about 140 million years ago due to tectonic forces, which created deep rifts in Earth’s crust. As the tectonic plates beneath these continents moved away from each other, magma from the Earth’s mantle emerged, forming new oceanic crust and gradually widening the gap between the two landmasses. This process eventually led to the formation of the South Atlantic Ocean, which filled the space between the newly-separated continents.
Signs of these monumental geological events are evident at both sites where the dinosaur footprints were discovered: the Borborema region in northeastern Brazil and the Koum Basin in northern Cameroon. Both areas feature half-graben basins—geological structures formed during rifting as the Earth’s crust pulled apart, creating faults. These basins contain ancient river and lake sediments that have preserved not only dinosaur footprints but also fossil pollen, indicating an age of around 120 million years.
Before Africa and South America separated completely, “rivers flowed and lakes formed in the basins,” Jacobs explained. “Plants fed the herbivores and supported a food chain. Muddy sediments left by the rivers and lakes contain dinosaur footprints, including those of meat-eaters, documenting that these river valleys could provide specific avenues for life to travel across the continents 120 million years ago.”
A Window into the Past
The discovery of these matching dinosaur footprints on two different continents offers more than just a glimpse into the past; it provides a tangible connection between South America and Africa before they became divided by the Atlantic Ocean. These footprints tell a story of migration, survival, and the dynamic processes that have shaped our planet over millions of years.
As researchers continue to study these ancient tracks, they hope to uncover more about the lives of the dinosaurs that made them and the environment they lived in. This discovery shows the importance of paleontological research in understanding Earth’s history and the profound changes it has undergone. The footprints left behind by these prehistoric giants serve as a reminder of a time when the world was a vastly different place, shaped by the forces of nature and the creatures that once roamed its surface.
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