An intriguing discovery by an international team of researchers led by SMU paleontologist Louis L. Jacobs has unveiled a stunning connection between South America and Africa millions of years ago. The team has found matching sets of dinosaur footprints from the Early Cretaceous period in Brazil and Cameroon, providing evidence of a time when land-dwelling dinosaurs freely roamed between the two continents before they split apart.

Over 260 footprints were unearthed in locations that are over 3,700 miles apart - Brazil and Cameroon. The footprints were imprinted into mud and silt along ancient rivers and lakes, serving as a fossilized testament of a time roughly 120 million years ago, when the supercontinent Gondwana still existed.

Detailed analysis of the footprints has revealed striking similarities. Not only are their ages and geological contexts alike, but their shapes are almost identical, indicating a common ancestry. The majority of the footprints belong to three-toed theropod dinosaurs, but a few were also made by sauropods or ornithischians.

Key to this discovery is the presence of a narrow stretch between present-day northeastern Brazil and the coast of Cameroon along the Gulf of Guinea. This region, known as the elbow of northeastern Brazil, provided one of the youngest and narrowest geological connections between South America and Africa, allowing animals on both sides to potentially traverse across it.

Dr. Jacobs elucidated, "Before the two continents drifted apart, animals could move freely across this connection. The rivers and lakes in the basin created by the rift between the two continents provided a pathway for life to travel and flourish. These muddy sediments preserved dinosaur footprints, offering a glimpse into the prehistoric world where herbivores thrived and meat-eaters roamed."

The unveiling of these footprints also sheds light on the geological events that led to the separation of Africa and South America. Approximately 140 million years ago, the process of continental rifting began, causing rifts to open up and form gashes in the Earth's crust. As the tectonic plates beneath the continents moved apart, magma from the mantle rose to the surface, creating new oceanic crust. Eventually, the South Atlantic Ocean filled the gap between the two continents.

The footprints found in the Borborema region of Brazil and the Koum Basin in Cameroon provide a tangible record of this incredible geological transformation. Half-graben basins, formed during the rifting process, contain ancient sediments from rivers and lakes, alongside the preserved footprints. These sediments also contain fossil pollen that further supports an age of 120 million years.

The study, published in honor of the late paleontologist Martin Lockley, not only highlights the remarkable convergence of dinosaur footprints in Brazil and Cameroon but also provides a fascinating glimpse into an era when South America and Africa were still connected. This discovery emphasizes the importance of exploring the Earth's geological history to uncover the secrets of our planet's prehistoric past.