300 million year old screw,..Who Built It?

In the summer of 1998, Russian scientists who were investigating an area 300 th southwest of Moscow on the remains of a meteorite, discovered a piece of rock which enclosed an iron screw.  Geologists estimate that the age of the rock is 300-320 million years.
At that time there were no  intelligent life forms on earth, not even dinosaurs  The screw, which is clearly visible in the head and nut, has a length of about cm and a diameter of about three millimeters.

Scientists initially thought that the screw was in a farm machine.  But the screw was firmly fixed in the rock.

The case of "error" was excluded because in addition, as shown by subsequent studies, the screw is there really a huge amount of time, since the iron atoms of the screw and the atoms of silicon (from which the rock consists mainly) have spread across the two ylika.Oi X-rays revealed that exist within the rock bolts and similar .. as well as two small round balls that have square holes.
This finding has been studied intensively in various scientific institutions of Russia - from geologists, physicists, paleontologists, mineralogists and proved that the screw was in the sediment before it is mounted on a rock.  All technicians who examined the findings are convinced that the screw has been artificially constructed and not a product of a natural process.