A mystery creature washed up on Orkney almost 200 years ago was "strikingly similar" to descriptions of Nessie, the Highlands Science Festival will hear.
Some experts said the beast was a dead basking shark
Geneticist Dr Yvonne Simpson, who hails from Orkney, has researched the Stronsay Beast.
Its carcass, which some said was that of a basking shark, was found off Stronsay in 1808.
Dr Simpson said the descriptions of its long neck were along the lines of those of the Loch Ness Monster.
She will give a joint talk with Loch Ness expert Adrian Shine during the science festival, which opened on Saturday.
The Stronsay Beast was first sighted on 25 September 1808 on rocks at Rothiesholm Head, on the south-east of the island, by a local fisherman.
Various others saw the carcass and fragments of it are preserved at the Royal Museum of Scotland in Edinburgh.
Some people suggested it was a basking shark or a large unidentified shark.
Orcadian Dr Simpson, who has a degree in evolutionary, environmental and biomedical genetics from the University of St Andrews and a PhD in the field of DNA damage repair from Edinburgh's pathology department, is fascinated by the stories.
Of her research comparing the two "monsters", she said: "Based on an analysis of eye-witness descriptions, Nessie and the Stronsay Beast are both massive aquatic creatures.
The oldest sighting of the Loch Ness Monster dates back to AD565 when St Columba was said to have seen a large monster in the River Ness
The term Nessie was created by a journalist after the first modern sighting in 1933
The Stronsay Beast measured (16 metres) 55ft
"The drawings of the Stronsay Beast carcass are strikingly similar in shape and size to the popular image of Nessie."
During her studies of the Orkney creature, Dr Simpson was impressed by the wealth of eye witness accounts and sworn testimonies given to justices of the peace.
She said: "Most of the original remains have been lost, the skull and 'paw' had been sent down to London in the 19th Century and were destroyed in the Blitz, so the only surviving parts that I could locate were in a storage at Edinburgh's Royal Museum.
"As a biologist I was intrigued by the rare opportunity to examine remains first-hand, but also as it is from Stronsay, and I grew up on another Orkney island, I felt this was an Orkney tale which had been forgotten, and which I wanted to uncover."
The festival runs until 17 November at venues in Inverness-shire, Dingwall and Applecross.