Dozens of archaeologists are undertaking excavation work in the caves of Atapuerca in Spain to find remnants of our ancient ancestors dating back more than a million years. It is hoped that the caves will reveal answers surrounding the prehistoric ancestors of Europeans, which could write a new chapter in the history of human evolution.

"The site covers a very long period of time, practically from when the first humans arrived in Europe, up to the present day," says Jose Maria Bermudez de Castro, one of the directors of the dig.

The site, which was classified as a world heritage site by UNESCO in 2000, has already offered up a human finger and jawbone dating back 1.2 million years – considered the remains of the oldest European ever found. Archaeologists, who have been working at the site since 1978, have also found skulls, bones and teeth belonging to Homo antecessor who lived between 850,000 and 950,000 years ago, and bits of Homo heidelbergensis, from around four hundred millenia ago. "It is the site that has yielded the most human remains in the world," says Juan Luis Arsuaga, another of the directors of the project.

However, the latest excavation project is focused on a search for human remains in the oldest parts of the site, one and a half million years old. In particular, they are hoping to find evidence of more prehistoric humans such as Neanderthals and Cro-Magnon man, of which they have found tools but no human remains, leaving a gap of some hundred thousand years.

After the dig is completed at the end of this month, researchers will spend months sifting through all the fragments they have been uncovering with the aim of reconstructing details of our prehistoric ancestors and the stories of the first Europeans to have walked the planet.

By April Holloway