Two pieces of fossilised tree trunk, which date back 150 million years, have been stolen from Gyllyngdune Gardens in Falmouth in what is thought to have been a premeditated raid.

The two fossils are worth about £200 each and were stolen overnight when the gardens were closed.

Head gardener Matt Stannard said: “Whoever has taken them knows exactly what they are and they must have had a van because they are very heavy.

“I don’t know how anyone could sell them other than over the internet, but personally I think someone has stolen them to add to their own fossil collection after taking a fancy to them.”

The two pieces have only been on display at Gyllyngdune for about two-and-a-half years after being brought out of storage at Fox Rosehill Gardens where they had been kept for many years. It is not known which kind of tree they originate from or how they came to be in Falmouth.

The fossils had been placed outside the greenhouse, next to the steps leading from the Princess Pavilion down into the gardens, and had been a firm favourite with school groups.

Their theft has been reported to the police and Matt is asking for anyone who may know of their whereabouts to call the police by dialling 101. Alternatively, they can be returned to the gardens.