THE footprint of a huge dinosaur has been discovered in a paving slab at a nature reserve now famous for its red squirrels.

National Trust ranger Sophie Giles came across the 140 million year old print while jogging around Brownsea Island in Poole Harbour.

The print has been identified as that of an iguanodon, a 36ft tall, 4,000lbs herbivore that walked the Earth during the late Jurassic period.

It was exposed in a slab of Purbeck stone that had been quarried from the nearby Isle of Purbeck and transported to Brownsea about 50 years ago.

Nobody had noticed the footprint before until Sophie stumbled upon it.

She said: "I was running and I go past this spot nearly every day. It had been raining and the water had pooled into this footprint and it was suddenly visible.

"I must have glanced at it so many times before and never noticed.

"It has been used as a paving slab that was imported from Purbeck many years ago. The person who installed it didn't recognise the significance at the time and it is only now we realise just how amazing it is."

Brownsea Island is a popular nature reserve and is famous for its colony of endangered red squirrels.

Dr Martin Munt, curator at the Dinosaur Isle Museum at Sandown, Isle of Wight, said: "When I first heard about the footprint I thought that must be wrong, a dinosaur print on Brownsea Island that's not going to happen.

"We can't be certain as to what sort of animal made it, but we can be fairly confident of it being iguanodontian, as bones found in those rocks can be identified as such.

"The footprint is in rock from Purbeck, so was probably part of building stone brought to the Island.

"The iguanodon is well known for being across southern England. It is quite widespread and understood to be prominent along our coast."

Members of the public will get the chance to see the dinosaur print when Brownsea Island re-opens next March.