Paleontologists lack the fossils they need to trace the evolutionary history of the Amazon region, a region characterized by unparalleled biodiversity. By exploiting data from a site known for over a century, Juan Carrillo, a researcher at the University of Fribourg, and his colleagues from other institutions, have made exceptional discoveries that shed new light on this little-known past.
The Amazon rainforest boasts incredible biodiversity, the result of a very long history punctuated by variations in climate and landscape. Like all tropical regions, it is characterized by a higher number of plant and animal species than anywhere else in the world. Fossils could help us to trace the thread of this evolution, but in these parts of tropical South America, there are few well-studied deposits.
An exceptional fossil site
Rare, but not non-existent! In what is now known as the Tatacoa Desert, Colombia, lies the La Venta fossil site, well known to paleontologists. Here, researchers have unearthed fossils dating back 13 to 11 million years, in an exceptional state of preservation. With their great diversity of fauna, these fossils attest to the existence of an ancient tropical forest. At that time, the northern part of the Andes had not yet risen, and the climate was considerably warmer than today.
Known but little studied
Paleontologists have known about the Tatacoa desert site for over a century, but the last major expeditions were several decades ago. Recently, an interdisciplinary group of researchers from Colombian and international institutions, including Juan Carrillo from the University of Fribourg, resumed paleontological studies on this site in close collaboration with the local community of La Victoria, a small rural town of around 3,000 inhabitants[JC1] .
Combing through this site and the ’old’ finds has enabled paleontologists to make some exceptional discoveries, such as the oldest relative of the Amazon River turtle, an ancient species of catfish and an exceptional fossil of an extinct saber-toothed marsupial. The results show that despite a century of research, there is still much to be learned from this site, which will help scientists understand how climate change and geological events, such as the uplift of the Andes, have influenced the evolution of tropical biodiversity.
A scientific as well as a local impact
Thanks to the joint work of scientists and young leaders from the local community of La Victoria, a new museum has recently been created. This contributes to the development of tourism in the town and also fulfils a number of educational missions, which are of great importance for the protection and study of paleontological heritage.
CARRILLO J. D. (ed.) 2023. - Neotropical palaeontology: the Miocene La Venta biome. Geodiversitas, vol. 45, arts 3, 6, 10, 12, 13, 15, 18, 25, 26.
Illustration credit: Guillermo Torres. Banco de Imágenes Ambientales (BIA). Instituto de Investigaciones de Recursos Biológicos Alexander von Humboldt.