Scientists pinpoint age of suspected human-Neanderthal hybrid child

Advanced radiocarbon dating has provided the most accurate age assessment yet for the “Lapedo Child,” one of the most provocative prehistoric human skeletons ever discovered. But the results of this study published March 7 in the journal Science Advances aren’t likely to settle an ongoing debate in the paleoarcheological community. 

Who is the Lapedo Child?

In 1998, researchers exploring the Lapedo Valley in central Portugal came across an unexpected find: a rock shelter situated at a cliffbase containing an ancient child’s nearly intact, ochre-stained skeleton along with items such as pierced shells and animal bones possibly used in a burial ritual. The team excavated and transported the bones to a lab, where they later determined the remains belonged to a roughly 4-year-old juvenile who lived approximately 24,500 years ago.

Further analysis revealed that the prehistoric “Lapedo Child” displayed a unique blend of physical characteristics that would soon make them famous: a mixture of both human and Neanderthal features suggesting a “hybrid” between the two evolutionary relatives. For example, the child’s lower limbs were much shorter than those of a modern human, and more resembled a Neanderthal. The skull, however, almost fully mirrored a Homo sapien, particularly the teeth and inner ears. At the same time, a pitted occipital region again recalled Neanderthals.

While interbreeding between modern humans and Neanderthals is documented in our species’ genealogical history, there was a problem: Neanderthals largely went extinct about 40,000 years ago–about 20,000 years before this child lived. While pockets of the genus lingered to intermingle with humans for thousands of years, the Lapedo Child’s approximate age made direct interbredding hard to believe for some paleoarcheologists.

The two sides have gone back and forth over the implications for decades. One camp argues the Lapedo Child is the progeny of human and Neanderthal parents, while the other faction contends they simply display genetic traits inherited from interbreeding further back in their family tree.

Hydroxyporline dating

Scientists previously tried to more precisely estimate the Lapedo Child’s age using radiocarbon dating methods four times, but failed each attempt. Now, over 25 years after the discovery, a team including some of the Lapedo Child’s original locators has managed to lock in a precise date range. They believe that the Lapedo Child lived somewhere between 27,780–28,850 years ago.

The breakthrough is thanks to a new method known as hydroxyporline dating. This approach focuses on specific amino acids, while also removing more contaminants than standard dating options can. Researchers also used hydroxyporline dating on some of the burial site’s animal bone samples that included rabbit, horse, and red deer.

Paleolithic implications

While this latest chapter in the Lapedo Child’s saga doesn’t necessarily confirm or deny their parentage, additional evidence uncovered in the years since the initial discovery certainly lends additional credence to the hybridization theory. Regardless, the new dating techniques offer a more concrete context for Lapedo Child’s time period, as well as the Paleolithic community that buried them. Researchers also believe hydroxyporline dating will soon help paleoarcheologists learn much more about humanity’s evolutionary past.

“The direct date for the Lapedo Child demonstrates that this compound-specific radiocarbon dating method can also be applied to poorly preserved samples that would otherwise fail routine pretreatment methods,” the authors wrote in their study, suggesting “other morphologically and culturally important Paleolithic human remains” like those at Mladeč Caves in the Czech Republic, as well as France’s Abri Pataud and Saint Césaire sites.