The Clovis people might not be the first Americans per se but they do appear to be the first widespread prehistoric culture to populate the US. We know that they were direct descendants of America's earliest migrants, that they originated south of the ice sheets in what is now Canada 13,000 or so years ago, and that they munched on mammoth and ancient elephant (gomphotheres) meat, but much of who they are, what they did, and how they disappeared is still a mystery.

This is partly because the archaeological evidence is so scant. Clovis-era artifacts are littered across the states, yet there is just one known burial site – the Anzick site in Montana, where the partial remains of an infant boy were laid to rest alongside various objects, including an antler and stone tools. Until now, the date of the remains and the date of the hoard has been contentious. Previous studies have suggested the body is younger than the surrounding treasure, but a new study published in the Proceedings of the National Academy of Sciences confirms that the remains and the artifacts were indeed buried at the same time. 

"One thing that has always been a problem has been the accurate dating of the human remains from the site," Michael Waters, director of the Center for the Study of the First Americans, explained in a statement. 

"The human remains yielded a younger age that was not in agreement with the ages from the antler artifacts which dated older than the human remains. If the human remains and Clovis artifacts were contemporaneous, they should be the same age."

To settle the issue (hopefully) once and for all, the team used a technique called Specific Amino Acid Radiocarbon Dating. This involves isolating a specific type of amino acid from human bones. Here, they isolated an amino acid called hydroxyproline. 

"This amino acid could only have come from the human skeleton and could not be contaminated," Waters said. This contrasts with previous efforts to date the bones, which put them at risk of contamination. 

The same process was then used to redate the antler bones, showing that both bones and artifacts are between 12,725 and 12,900 years old – or, as Waters puts it, from "right in the middle to the end of the Clovis time period" between 13,000 and 12,700 years ago.

Now that the dating issues of the site have been resolved, the researchers hope the results will help geneticists map the migration of people in the Americas. The Clovis people are directly related to 80 percent of all living Native Americans in North America and closely linked to the remaining 20 percent, which makes this culture an especially important piece in the genetic puzzle.