Matching dinosaur footprints. Credit: SMU.
In a groundbreaking discovery, an international team of researchers has identified matching sets of dinosaur footprints on two continents – South America and Africa.
The team, led by Southern Methodist University (SMU) palaeontologist Louis L. Jacobs, have offered fresh evidence of the ancient connections between these now distant lands.
The footprints, more than 260 in total, were unearthed in Brazil and Cameroon, revealing where dinosaurs roamed freely before the supercontinent Gondwana split, setting the stage for the formation of the Atlantic Ocean.
Earth’s ancient landscape
The discovery is particularly significant because it highlights a time when South America and Africa were part of the same landmass.
“We determined that in terms of age, these footprints were similar,” Jacobs stated, adding that the footprints’ geological and tectonic contexts were almost identical. This finding highlights the close proximity of the two regions before they were divided by the forces of plate tectonics.
The footprints were made approximately 120 million years ago by dinosaurs crossing what was then a unified continent, Gondwana. This supercontinent eventually broke off from Pangea, leading to the gradual separation of Africa and South America. The footprints were preserved in mud deposits along ancient rivers and lakes, now located more than 6,000 kilometres apart.
One of the most intriguing aspects of the study is the focus on the “elbow” of northeastern Brazil and the adjacent coastline of Cameroon along the Gulf of Guinea.
Jacobs explained, “The two continents were continuous along that narrow stretch, so that animals on either side of that connection could potentially move across it.” This narrow land bridge was one of the last connections between the two continents before they finally drifted apart.
Most of the discovered footprints belong to three-toed theropod dinosaurs, with some possibly left by sauropods or ornithischians, according to Diana P. Vineyard, a research associate at SMU and co-author of the study.
Geological and biological clues to dinosaurs and the past
The locations where the footprints were found – Brazil’s Borborema region and Cameroon’s Koum Basin – share not only the dinosaur tracks but also other geological features. These areas contain half-graben basins, geological structures formed as the Earth’s crust pulled apart during the rifting process that eventually led to the formation of the South Atlantic Ocean.
These basins also hold fossil pollen, dating back 120 million years, which provides further evidence of the age and environment in which these dinosaurs lived. Before the continents fully separated, these basins were home to rivers and lakes that supported diverse ecosystems.
“Plants fed the herbivores and supported a food chain,” Jacobs noted, emphasising how these ancient environments served as corridors for life to move across what would become two separate continents.
The study, which included contributions from experts at Harvard University, Northwestern University, and the Universidade Federal do Rio de Janeiro, was published as part of a tribute to the late palaeontologist Martin Lockley. Lockley was renowned for his work on dinosaur tracks and footprints, and this latest discovery adds another chapter to our understanding of how these ancient creatures once navigated the globe.
This remarkable finding not only deepens our understanding of Earth’s geological past but also serves as a vivid reminder of the dynamic processes that have shaped our planet over millions of years.
