More than 12,000 years ago, South America was dominated by sabre-toothed cats, sloths, giant bears and other large animals, or “megafauna.” They lived happily alongside humans for close to 3,000 years. Suddenly, the populations of these amazing creatures started declining about 12,300 years ago, and they disappeared within a short time-frame of just 300 years towards the end of the last Ice Age.

Megafauna Extinction Driven By Climate Change

Scientists challenge the Blitzkrieg theory of megafauna extinction

What drove them to extinction? Previously, there was this “Blitzkrieg” theory that suggested humans moved to South America in a “Blitzkrieg” way and hunted the megafauna into extinction. But a new study published in the journal Science Advances reveals that the extinction was driven mainly by climate change.  Scientists led by Professor Alan Cooper of the University of Adelaide studied ancient DNA from carbon-dated fossils found at sites across South America to trace the genetic history of the populations.

Scientists found that the megafauna went extinct about 12,300 years ago. However, humans had begun spreading across the Americas more than 15,000 years ago. Human fossils recovered from Monte Verde near Patagonia were 14,600 years old. So, the giant animals lived with humans for close to 3,000 years where nothing happens, Professor Cooper told the ABC News.

The role of humans can’t be ruled out

The international team of scientists also concluded that the megafauna extinction coincided with rapidly rising temperatures. The climate in South America started warming rapidly 12,300 years ago after a prolonged cold period. The warming caused changes in vegetation with more forests and rainfall that were not suitable habitats for giant beasts.

However, it is too early to rule out the possibility of human involvement considering the animals went extinction in a surprisingly short time-span of just 300 years. It’s possible that humans became more active as the climate warmed, leading to a steep rise in human population and hunting. Scientists said more evidence was needed to understand the role of humans at the time.