Dinosaur footprints reveal secrets from a distant past. The discovery of identical tracks on two continents now separated by the Atlantic provides insight into prehistoric migrations.
Left: Theropod footprint from the Sousa Basin, Lower Cretaceous of northeastern Brazil. Credit: Ismar de Souza Carvalho.
Right: Theropod tracks from the Koum Basin in Cameroon. Credit: SMU.
In Brazil and Cameroon, dinosaur footprints dating back 120 million years offer a valuable glimpse into species distribution during the Lower Cretaceous. Over 260 similar footprints have been found, suggesting a land bridge existed between these two regions during the time of the supercontinent Gondwana.
Paleontologists have identified theropod tracks, as well as some footprints from sauropods and ornithischians. The morphological characteristics of these footprints, imprinted in fluvial and lacustrine sediments, show a striking similarity.
Researchers emphasize that these footprints come from ancient contact zones between Africa and South America. The regions of Borborema in Brazil and the Koum Basin in Cameroon, though separated today, once shared similar geological structures, resulting from the fragmentation of the supercontinent.
The underlying geological formations, such as semi-graben basins, attest to the tectonic dynamics that led to the formation of the South Atlantic Ocean. This geological configuration shows how dinosaurs could utilize terrestrial corridors before tectonic forces created an oceanic barrier.
A long ornithopod trackway at Passagem das Pedra in the Sousa Basin, preserved in Lower Cretaceous floodplain deposits.
Credit: Ismar de Souza Carvalho
This discovery enriches our understanding of continental drift and its impact on species distribution. Fossil footprints thus become direct witnesses to the major geological transformations that have shaped the Earth. The study highlights the evolution of prehistoric ecosystems and the environmental conditions favorable to dinosaur life. Ancient fluvial and lacustrine environments offered crucial resources to these creatures.
By linking paleontological and geological data, researchers enable a better reconstruction of ancient landscapes. This multidisciplinary approach helps to understand how continental drift influenced prehistoric biodiversity.
The results of this research, published by the
New Mexico Museum of Natural History & Science, provide concrete evidence of how dinosaurs moved between continents before their separation. These footprints offer new insights into the dynamics of continental masses and their impact on terrestrial life.
Author of the article: Cédric DEPOND