THE WORLD’S oldest egg is going under the hammer.

The extremely rare egg of the extinct elephant bird is expected to raise about £50,000 when it is auctioned at a sale of specialist natural history collectables in Billingshurst later this year.

The giant egg, which is as big as 100 hens’ eggs and bigger than seven ostrich eggs, is one of only a handful of undamaged eggs left by the huge birds, which were native to Madagascar.

Summers Place Auctions is expecting the lot to be a cracker, as the egg is thought to be the only one in the world up for private sale.

Curator Errol Fuller, who has written several books on rare extinct birds and is an expert in the field, is particularly egg-cited about the sale.

He said: “The egg of one of these birds is simply a miracle. It’s over a foot in length.

“There are probably only about 60 or 70 in existence in the world and almost all of them are owned by museums.

“To see one up for private sale is very rare. It is the largest egg ever known – bigger than any known dinosaur egg.

“Engineers have calculated that structurally and functionally it is impossible for an egg to be any larger.

“It comes from Madagascar and these birds became extinct in around 1600 so it must be more than 500 years old.

“Sometimes the eggs are found buried in the sand, semi-fossilised. This one had clearly been used as a water container as it is hollow and was handed down from generation to generation.

“It’s much tougher than a chicken egg, but they still get broken. This one is perfectly intact.”

The egg will be sold along with a collection of unusual natural history artefacts. A stuffed, extinct 100-year-old passenger pigeon is also up for auction and is expected to sell for between £4,000 and £6,000.

Other unusual taxidermy included in the sale is a tiger’s head in a case and a “unicorn” created from a horse, a narwal tusk and a bear skeleton.

The Evolution Sale will be held at Summers Place Auctions, Billingshurst, on November 26. Viewings will be held from November 21 to 25 and on the morning of the sale.