This is such a remarkable butterfly that scientists are wondering how it has gone unnoticed for so long.

It is a relatively large insect, measuring some eight centimetres across. True to its name, the swallowtail butterfly has two elongated edges projecting from the hind wings, which trail as it flutters through the canopy of the forest in which the species was found.

It has striking black and white zigzags emblazoned on the top or its wings, and a cream and black speckled pattern underneath. All of this is gilded with soft yellows and blue eye spots.

John Tennent, a scientific associate at the Museum, says, 'The discovery of a new swallowtail in the Pacific is hard to believe.

'The new swallowtail is a big butterfly, recognizable from a distance. There were previously only two swallowtail butterflies known from the region, endemic to Fiji and Samoa. Both are large but dull in appearance.

'To find a third as large and colourful and unusual, with its long, sword-like tails really is remarkable.'

An incredible find

The butterfly was actually first found and photographed by the ornithologist Greg Kerr, who was working on the Natewa Peninsula on the Fijian island of Vanua Levu in 2017.

So striking was the butterfly that lepidopterists who first saw the photographs thought the images may have been faked. It didn't seem plausible that such an insect could have gone unnoticed all this time.