The fossil of a fish was discovered by Damion Whitton and the minute he saw it he knew it was something special.
"The rock just looked different, special, and as soon as I saw the scales I knew it had to go to an expert," said Damion.
But recovering the rock, from a water culvert around the Towneley Park area, proved to be a task in itself as it weighs between 70 and 80kg, around 12 stone.
Damion enlisted the help of friends, Bruce-Lee Knowles and Chris 'Kipper' Taylor who are also fellow founders of the explorers group they set up last year called Northern Monkeys.
And when they took the fossil to be examined by a paleontologist in Rossendale, Damion's instinct proved to be right, as the expert declared it be a rare find of fish known as a Rhabdoderma.
It lived in the Carboniferous and Early Triassic period up to 400 million years ago and its fossils have been found in Europe, Madagascar and North America.
The fossil is now destined for a museum in either Manchester or London where it will go on display for fossil hunters to marvel at.
Damion added: "When I posted it in the fossil groups I belong to on social media they were shocked because it is such a rare find."