Footprints from dinosaurs found on opposite sides of the Atlantic
A team of researchers led by SMU paleontologist Louis L. Jacobs has found matching footprints of Early Cretaceous dinosaur footprints on what are now two different continents. Over 260 footprints were found in Brazil and Cameroon showing where land animals including dinosaurs could freely cross between South America and Africa millions of years before the two continents broke apart.
“We determined that in terms of age, these footprints were similar,” Jacobs said. “In their geological and plate tectonic contexts, they were also similar. In terms of their shapes, they are almost identical.”
The footprints were “impressed” in the mud and slit along ancient lakes and rivers. They were found over 3,700 miles away from each other and were left by dinosaurs that lived 120 million years ago on what was then a single supercontinent known as Gondwana. This continent had broken from the larger landmass of Pangea.
Africa began to split from South America around 140 million years ago, leaving gashes in the Earth’s crust.
“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,” 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.”
Most of the footprints were left by three-toed theropod dinosaurs, the family that includes tyrannosaurus and velociraptor. A few may have been made by sauropods, the long-necked giants such as diplodocus, or ornithischians, a family that includes a vast group of herbivores, according to research associate at SMU and co-author of the study Diana P. Vineyard,.
Signs of some of the major events in the earth’s crust were found between both locations where the dinosaur footprints were found – at the Borborema region in the northeast part of Brazil and the Koum Basin in northern Cameroon. Geological structures called half-graben basins, are present in both areas and contain ancient river and lake sediments, as well as footprints of dinosaurs.
Image: Ballista at en.wikipedia
