''The Kosmopoisk Group has not said what the screw is made of, or given any detailed information about it.
The self-styled group, which is also known as Spacesearch and the Russian Scientific Organisation, conducts expeditions to sites that are believed to have extraterrestrial activity or unusual creatures - and has a mixed reputation. ''
The leading hypothesis from experts who have seen photos of the stone is that the ‘screw' is actually the remains of an ancient sea creature called a crinoid.
''The screw-like shape may actually be the reversed-shape of the creature, which gradually dissolved while the rock formed around it.
Some 600 species of Crinoids are now extinct but the creatures live on in different forms in modern seas. They have five arms to snatch passing prey and a hidden mouth on the top.
It is thought that the fossilised creature in the mysterious rock is a form of ‘sea lily’ – a type of crinoid that grew a stalk when it became an adult, to tether itself to the seabed.''
''It would be great to think we could find such ancient evidence of a spaceship visiting us so long ago, but we have to consider whether extra-terrestrial spacecraft builders would use screws in the construction of their craft.
‘It also seems that this story is probably a hoax that is being spread by the internet, and reflects our desire to believe that extra-terrestrials have visited us in the past and are still visiting us today in what we now call UFOs.’
