Swiss surrealist artist Hans Rudolf Giger was sought out by Scott to design the creatures for 'Alien' after he saw Giger's artwork Necronom IV, one among his many designs that are said to have been based on the fossils, reported Daily Mail.
Giger's designs - one of which was seen bursting out of a character's chest on screen - went on to win his team an Academy Award for Best Achievement for Visual Effects on the 1979 film and the franchise that followed.
But the strange fossil is actually the remains of an early form of life that existed on Earth 300 million years ago.
The extremely rare fossil, which went on display at the Aathal dinosaur museum in Switzerland, was stolen and later returned - put into the museum's post box tucked inside a padded envelope.
Museum curator Dr Thomas Bolliger said, "It was comparatively undamaged - although one of the arms had broken off. It really is a remarkable fossil and shows two separate species of a spineless animal that lived at the bottom of the sea around 300 million years ago."