A fossilized Neanderthal skeleton found in France has unveiled an uncharted branch of the Neanderthal lineage, separate from other known Neanderthal groups. The remains, discovered in the Rhône Valley's cave system in 2015, were initially believed to belong to early Homo sapiens. However, a recent study has revealed that the cave also served as a home to a distinct population of Neanderthals around 40,000 to 45,000 years ago, towards the end of their existence.

Named "Thorin" after a character from J.R.R. Tolkien's universe, this mysterious Neanderthal is unlike any other previously unearthed. Despite its estimated age, Thorin's genetic makeup closely resembles that of early Neanderthals living over 100,000 years ago, suggesting that this population remained isolated from others for at least 50,000 years.

Paleoanthropologist Ludovic Slimak, co-first author of the study from the University of Toulouse, explains that Thorin introduces an entirely unknown Neanderthal population and challenges our understanding of the last great extinction event of humanity.

To explore the magnitude of the difference between Thorin and other late Neanderthals, Slimak likens it to the divergence between a tiny dog and a wolf, resulting from 50,000 years of evolutionary changes. Despite the significant differences, both populations can still be classified as the same species.

Senior author of the study, Martin Sikora from the University of Copenhagen, compares the divergence between Thorin and other late Neanderthals to the diversity observed among modern human populations as they migrated out of Africa. This implies that similar diversity could have existed among different Neanderthal groups.

The striking aspect of Thorin's discovery is that other late Neanderthal populations lived in close proximity, yet there appears to have been little or no interaction between them. The researchers entertained the possibility that the dating of the cave's sediment was inaccurately determined, but isotopic analysis of Thorin's bones and teeth confirmed that he lived in a frigid climate during the Ice Age.

Despite living just a short distance apart, Thorin's population and others did not intermingle, raising questions about the biological and psychological differences between Neanderthals and Homo sapiens. While it would be unthinkable for our species to maintain such isolation, the study suggests that Neanderthals may have perceived the world in a fundamentally different way.

The groundbreaking study, published in the journal Cell Genomics, highlights the significance of Thorin's discovery in challenging our previous understanding of Neanderthals and the last phase of their existence as a species. With its unique genetic makeup and the isolation of its population, Thorin provides a glimpse into a previously unknown Neanderthal population, reshaping our understanding of our ancient human relatives and the dynamics of their extinction.