The "screw" is actually the fossilized remains of a type of ancient, simple sea animal.
edit on 20-1-2013 by inivux because: (no reason
given)
According to Yulia Zamanskaya, when a resident of Vladivostok was lighting the fire during a cold winter evening, he found a rail-shaped metal detail which was pressed in one of the pieces of coal that the man used to heat his home. Mesmerized by his discovery, the responsible citizen decided to seek help from the scientists of Primorye region. After the metal object was studied by the leading experts the man was shocked to learn about the assumed age of his discovery. The metal detail was supposedly 300 million years old and yet the scientists suggest that it was not created by nature but was rather manufactured by someone. The question of who might have made an aluminum gear in the dawn of time remains unanswered.