Archaeologists have found the earliest human footprints known outside Africa, at Happisburgh on the Norfolk coast.

Dating back 800,000 years, the prints are thought to have been made by five individuals, including both adults and children.

They were identified by a team of scientists led by the British Museum, Natural History Museum, and Queen Mary University of London, after heavy seas removed beach sands to reveal a series of hollows in the silt at low tide.

Analysis of digital images of these hollows confirmed that they were ancient human footprints, direct evidence of the earliest known humans in northern Europe. In some cases the prints were so clear that the heel, arch, and even toes could be identified.

‘At first we weren’t sure what we were seeing, but as we sponged off the seawater, it was clear that the hollows resembled prints, perhaps human footprints, and that we needed to record the surface as quickly as possible before the sea eroded it away.’

He added: ‘This is an extraordinarily rare discovery. The Happisburgh site continues to re-write our understanding of the early human occupation of Britain, and indeed, of Europe.’

The Happisburgh footprints are among the oldest found in the world to-date; only those at Laetoli in Tanzania (c.3.5 million years old) and at Koobi Fora in Tanzania (c.1.5 million years old) are earlier.

Dr Isabella De Groote from Liverpool John Moores University studied the Norfolk examples in detail.

‘In some cases we could accurately measure the length and width of the footprints and estimate the heigh of the individuals who made them,’ she said. ‘In most populations today and in the past, foot length is approximately 15% of height. We can therefore estimate that the heights varied from about 0.9m to over 1.7m – this height range suggests a mix of adults and children with the largest print possibly being a male.’

For the past 13 years, excavations at Happisburgh have produced stone tools and butchered animal bones that represent the earliest evidence of human activity yet identified in Britain. The age of the site is based on examination of glacial deposits overlying the finds, which contain extinct animals and environmental evidence dating back more than 800,000 years. The footprints come from the same deposits.

‘Although we knew that the sediments were old, we had to be certain that the hollows were also ancient and hadn’t been created recently,’ said Dr Simon Lewis of Queen Mary University of London. ‘There are no known erosional processes that create that pattern. In addition, the sediments are too compacted for the hollows to have been made recently.’

Work at Happisburgh continues, with coastal erosion revealing new sites but the encroaching sea also threatening existing discoveries. The footprints have unfortunately already been washed out, but it is hoped that more will be revealed in the future.

These findings were published today in the science journal PLOS One, while the team’s work at Happisburgh also features in the Natural History Museum’s upcoming exhibition (opens 13 Feb), Britain: One Million Years of the Human Story.

You can read all about Happisburgh’s extraordinary prehistoric archaeology, and what it tells us about the earliest chapters of human activity in Britain, in CA 288.