First Britons faced mammoths and sabre-toothed cats

When the first humans arrived more than 840,000 years ago Britain was already home to southern mammoths Illustration: Cian O'Luanaigh/Guardian Photograph: Cian O'Luanaigh/guardian.co.uk An artist's impression of Happisburgh, Norfolk, as it might have looked more than 800,000 years ago. Remnants of their stone tools were found close to the seashore where coastal erosion has exposed a treasure trove of fossils, including remains of giant beavers, mammoths, red deer and primitive horses Photograph: John Sibbick/PA Photograph: John Sibbick/guardian.co.uk Excavations on the Norfolk coast near Happisburgh in 2006 Photograph: Phil Crabb/Natural History Museum, London Photograph: Phil Crabb/guardian.co.uk Artefacts were found in a layer of brown gravel, beneath layers of sand and silt Photograph: Phil Crabb/Natural History Museum, London Photograph: Phil Crabb/guardian.co.uk At the time of the ancient human occupation at Happisburgh, the Thames drained into the North Sea, 150 kilometres to the north of its current estuary. The broken lines indicate the ancient coastline. In between is the land bridge that once connected Britain to mainland Europe Photograph: Parfitt et al/Nature Photograph: Parfitt et al/guardian.co.uk Some of the flint tools on display at a press conference at the Royal Institution in London earlier today Photograph: Sang Tan/AP Photograph: Sang Tan/guardian.co.uk A mammoth tooth (centre), a hyena dropping (left), and the jaw of an extinct giant beaver Photograph: Sang Tan/AP Photograph: Sang Tan/guardian.co.uk Palaeontologist Simon Parfitt examines the fossilised hyena dropping Photograph: Sang Tan/AP Photograph: Sang Tan/guardian.co.uk