Ancient Extinct Tortoise Fossil May Tell Us About The Rise of the Andes
There is a link between the ancient fossil shells as well as the history of the Andes mountains. The fossils show that the tall plateaus in the Andes were once less than a kilometer above sea level about 13 million years ago.
"We're trying to understand how tectonic plate activity and changing climate affected species diversity in the past," said Darin Croft, one of the researchers, in a news release. "One way all this diversity we see in the South American tropics today was generated was through elevation. Mountains create many different climates and ecosystems in a small area, which promotes speciation."
Scientists found the remnants of the tortoise as well as the turtle in the stark, arid Andes Mountains.
Belonging to the same genus as the Galapagos tortoise, Chelonoidis, this extinct freshwater turtle was of the genus Acanthochelys. Its members today are found throughout tropical South America.
"It's like that the ancient tortoise wouldn't have been able to survive in altitudes that are found today in the Andes due to the cooler temperatures. This may mean that the Andes were far lower than they are today," according to scienceworldreport.
The process of subduction, in which one tectonic plate is shoved under another helped to form the Andes Mountains. However, it is not clear how speedily the mountains rose to their current height.
Had the Andes Mountains been less than 1 kilometer high in the late Miocene, as suggested by the fossil, their effect on global circulation would have been less if they were two or three times as high. It would have been nearer to their elevation today, near Quebrada Honda".
The findings give an insight into the climate then and now. They are published in the Journal of South American Earth Sciences.