An international team of researchers, led by Southern Methodist University (SMU) paleontologist Louis L. Jacobs, has made a groundbreaking discovery that provides significant insights into the prehistoric world. The team found matching sets of Early Cretaceous dinosaur footprints on what are now two different continents, Brazil and Cameroon, shedding light on how dinosaurs once roamed freely across a vast supercontinent.
The Remarkable Discovery
The discovery, which includes more than 260 footprints, reveals that these land-dwelling dinosaurs were able to traverse freely between South America and Africa millions of years ago, before the two continents split apart. The footprints were found approximately 3,700 miles (6,000 kilometers) away from each other, embedded in mud and silt along ancient rivers and lakes. These tracks date back to about 120 million years ago when South America and Africa were part of a single landmass known as Gondwana.
Louis L. Jacobs, the lead researcher, highlighted the similarities between the footprints found on both continents. “We determined that in terms of age, these footprints were similar,” Jacobs explained. “In their geological and plate tectonic contexts, they were also similar. In terms of their shapes, they are almost identical.”
Geological and Paleontological Significance
The findings offer a fascinating glimpse into the prehistoric world, particularly the period before the continents began drifting apart. Gondwana itself was once part of an even larger supercontinent, Pangea, which began breaking up around 200 million years ago. The split between South America and Africa started around 140 million years ago, during the Early Cretaceous period.
The footprints were discovered in the Borborema region of northeastern Brazil and the Koum Basin in northern Cameroon. These locations are of particular interest because they were once part of a narrow geological connection between the two continents. Jacobs explained that one of the youngest and narrowest geological connections between Africa and South America was the elbow of northeastern Brazil nestled against what is now the coast of 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,” he said.
Dinosaur Species and Their Tracks
The majority of the footprints were made by three-toed theropod dinosaurs, which were carnivorous and walked on two legs. Theropods include some of the most well-known dinosaurs, such as Tyrannosaurus rex and Velociraptor. The research team also identified footprints likely made by sauropods, large, long-necked herbivores, and ornithischians, another group of herbivorous dinosaurs.
Diana P. Vineyard, a research associate at SMU and co-author of the study, noted the diversity of the dinosaurs that left these tracks. “Most of the dinosaur fossils were created by three-toed theropod dinosaurs. A few were also likely made by sauropods or ornithischians,” Vineyard said.
Evidence of Major Geological Events
The discovery of these footprints is not only significant for understanding dinosaur behavior and movement but also for understanding the major geological events that shaped the Earth’s continents. The rifting process that eventually separated South America and Africa left behind gashes in Earth’s crust, known as rifts, which later filled with magma from the Earth’s mantle. This magma cooled and formed new oceanic crust, eventually creating the South Atlantic Ocean that now separates the two continents.
Signs of these major geological events are still visible in the regions where the footprints were found. Both the Borborema region in Brazil and the Koum Basin in Cameroon contain half-graben basins—geological structures formed as the Earth’s crust pulled apart during rifting. These basins, filled with ancient river and lake sediments, contain not only dinosaur footprints but also fossil pollen that dates back to 120 million years ago.
A Tribute to a Pioneer in Paleontology
The study, which was published by the New Mexico Museum of Natural History & Science, also serves as a tribute to the late paleontologist Martin Lockley. Lockley was renowned for his work on dinosaur tracks and footprints, and his contributions to the field have been invaluable in advancing our understanding of these ancient creatures.
Conclusion
This discovery of matching dinosaur footprints on two continents is a remarkable reminder of how interconnected the Earth’s landmasses once were. The footprints not only tell the story of the dinosaurs that made them but also of the massive geological forces that shaped our planet. As researchers continue to study these ancient tracks, they will undoubtedly uncover more secrets about the world of 120 million years ago, offering new insights into the history of life on Earth.
Source: Southern Methodist University