Fiona Riddall Bell discovered a small portion of the tusk poking up through the ground more than 20 years ago as she was clearing her garden, and, thinking it was merely an odd-looking piece of root, decided to store it in a garden shed after it had been dug up. Decades passed without giving the item much thought until, on a visit to the Museum of Archaeology and Anthropology, in Cambridge, Fiona and her daughters Cecilia, 12, and Felicity, 9, spotted an aurochs horn and immediately thought of the root back home in The Avenue. She said: The museum staff thought otherwise and had it authenticated as a tusk by someone from the Natural History Museum, in London. For a while we were entertained by thoughts of how an obviously ancient part of an elephant could have arrived in the garden. Then, last year, a friend of Fionas, Kate Hadley - a member of the team at The Porch Museum, in Godmanchester put her in touch with a mammoth expert who works with the Norris Museum, in St Ives. Dr Chris Thomas agreed to take a look at the tusk and confirmed that the item belonged to a mammoth, a species which died out in Europe about 10,000 years ago. Fiona said: The girls and I were rather astonished to discover that this was actually the tusk of a young mammoth. Since the revelation, the tusk has spent a year on the Learning Bus, an educational resource that visits primary schools in Cambridge, where it has handled by thousands of children. Fiona says it is unlikely that any more of the mammoth remains in her garden and suspects the tusk may have been dredged from a river bed many years ago. She added: We shall never know where the mammoth died Im afraid, we were just fortunate to find ourselves with a little trace of his having existed. Most recently, the tusk was part of a display at The Porch Museum, during a bank holiday exhibition. The Norris Museum, based in St Ives, brought some of its collection to The Porch on May 1 and residents were invited along to view a range of historical artefacts, from pre-historic fossils and Roman-era items, right through to fen skating memorabilia.