Analysis of the bones of an ancient and now extinct bird has provided evidence that humans lived on the island of Madagascar more than 6,000 years earlier than previously believed.
James Hansford, of the Zoological Society of London, and colleagues conducted an analysis of the bones of extinct Madagascar elephant birds. The ostrich-like elephant creatures, which were once native to the island, stood more than 3 meters and weighed more than 350 kilograms.
The researchers found that the cuts and depression fractures on the bones are consistent with human hunting and butchery. The marks also suggest that human hunters likely knocked the birds to the ground by hitting them very hard in the legs, before making the fatal blow. Hansford said that the cut marks on the bones could not be attributed to natural erosion process.
“Tool use on fresh bones leaves unmistakable patterns as knives cut across the surface of the bones when cutting away flesh or as large tools chop down to cut ligaments and tendons to break apart limbs,” Hansford told Newsweek.
Researchers determined the age of the bones using radiocarbon dating techniques. They extracted collagen from the bones, which was then analyzed by two Accelerated Mass Spectrometry Radiocarbon dating facilities.
The results showed that the giant flightless birds were killed about 10,000 years ago, which means that humans were already in Madagascar 6,000 years earlier than previously thought. Hansford and colleagues published their findings in the journal Science Advances on Sept. 12.
Prior to this new work, the oldest evidence of human presence and activity on the island were 2,500-year-old cut marks on the bones of a giant lemur, and a batch of 4,000-year-old tools that were discovered in the northern part of the island.
“Our evidence for anthropogenic perimortem modification of directly dated bones represents the earliest indication of humans in Madagascar, predating all other archaeological and genetic evidence by >6000 years and changing our understanding of the history of human colonization of Madagascar,” the researchers wrote in their study.
The study also offered insights on the extinction of megafauna, particularly on the island. Scientists have suspected that climate change was responsible for the demise of these creatures, and humans were an unlikely cause of their extinction. The study provided evidence that humans were present on the island several centuries before these giant animals became extinct.
The bones of the elephant birds that the researchers studied were found in Christmas River in 2009, a site rich in relics of megafauna.