Some have argued the remains were those of a basking shark
Fresh clues have been found to help a scientist in her efforts to identify a mystery creature found on Orkney.
Geneticist Dr Yvonne Simpson has researched the Stronsay Beast and will reveal her latest discoveries at the Orkney International Science Festival.
The creature's carcass, which some said was that of a basking shark, was found off Stronsay in 1808.
Dr Simpson has said the descriptions of its long neck were along the lines of those of the Loch Ness Monster.
Festival director Howie Firth said few tissue samples had survived, but through her studies the geneticist had found several other items recovered from the remains.
The festival opens on Thursday and Dr Simpson will give her talk on 12 September - the 200th anniversary year of the day the creature was found.
Last year, she gave a joint talk with Loch Ness expert Adrian Shine during the Highlands Science Festival.
The Stronsay Beast was first sighted in 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 told the BBC Scotland news website last year: "Based on an analysis of eye-witness descriptions, Nessie and the Stronsay Beast are both massive aquatic creatures.
"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.