Some Sloths Have Slowly Evolved from Walking on Earth to Living in Trees. It Took Them 22 Million Years!

After analyzing a well-preserved bone from an ancient giant ground sloth, researchers found impressive facts. The creature’s fossil was first discovered by Charles Darwin in South America. It then received the name Mylodon darwinii to mark the scientific achievement.

Researchers used a bone fragment that is 13,000 years old. They reconstructed DNA fragments to get high-quality information on the mitochondrial genome and nuclear genomic.

Two Species of Sloths Diverged 22 Million Years Ago

The results showed that, for the first time, scientists could prove that the giant ground sloth –  that went extinct almost 10,000 years ago, is the more physically active relative of today’s two-fingered sloth. As we all know, the modern two-fingered sloth is among the slowest mammal on Earth.

The study was recently published in the Proceedings of the Royal Society B. Hendrik Poinar is the lead author of the study. He is also the director of the McMaster Ancient DNA Centre and principal investigator at the Michael G. DeGroote Institute for Infectious Disease Research. He explains the connection between the tree-dwelling sloth and the giant ground sloths:

“Our study confirms the convergent evolution of the two, tree-dwelling modern sloths from two distinct lineages of extinct giant ground sloths. This means tree-living evolved independently, twice, which is remarkable.”

The bone sample was incredibly well-preserved, coming from the Mylodon Cave in Chile, where scientists found many fossils of ground sloths. The conditions inside the cave helped to preserve the bones, claws and even feces and mummified skin covered in blond fur!

Frédéric Delsuc is the co-author of the paper and Director of Research at the Centre National de Recherche (France). He explains that the perfect bone sample will be useful in future research:

“The incredible conservation of the bone sample we used in this study offers promising prospects for sequencing the full genome of this extinct species because of the high percentage of DNA that it contains. This will certainly generate more insights and information into their unique features and ultimate extinction.”