In 1933, Londoner George Spicer was driving along a new road at Loch Ness when he claimed to have seen ‘the most extraordinary form of animal’ cross in front of his car.

Standing four feet tall, and with a long wavy neck slightly thicker than an elephant's trunk the creature lurched off into the undergrowth and vanished, leaving behind only a legend that has endured for nearly 100 years.

Now researchers at the University of St Andrews think they have discovered why myths of long-necked creatures like ‘Nessie’ have rocketed in recent centuries. And Georgian fossil hunters appear to be blame.

The academics found that after the first dinosaurs and ancient marine reptiles were discovered by paleontologists, and put on display at museums across Britain in the early 19th century, the number of reports of spindly-necked terrors soared.

Although stories of sea creatures date back through history, before 1800 just 10 per cent of cases described animals with a long neck. But by the 1930s, when Spicer saw his ‘monster’ the number was close to 50 per cent.

The study hints that a kind of ‘collective illusion’ had gripped the national consciousness to such an extent that any unexplained shape, splashing about in the water, was attributed to Jurassic and Mesozoic monsters.