Its ferocious roar stops visitors in their tracks and children instinctively reel back as the giant raptor flicks its tail and opens its giant jaws.

One tormenting father says: 'Here's a tasty four year old.'

The terrifying Tyrannosaurus Rex and its equally ferocious 'brother' Allosaurus are the latest arrivals at Dinosaur Adventure – and put Jurassic Park into Weston Park.

For unlike the park's original, much-loved stationary dinosaurs the new kids on the block – actually dating back 150 million years in the case of Allosaurus – come with realistic moving parts.

Park managing-director Martin Goymour combed the world for the latest additions and the pair, controlled by sophisticated electronics, have been bought from a Chinese company at a cost of £30,000.

They have been unveiled, one by the entrance and one next to the indoor play area, Dinomite, in time for the school holidays.

'It's amusing to see children's reaction when they come to life and roar – but in their first three weeks here everyone has loved them,' said Mr Goymour.

A third animatronic dinosaur, an Ankylosaurus, will be arriving in August and Mr Goymour plans to add to the collection at a rate of two a year.

He said: 'We first saw them when we visited a major European leisure and tourism show in Berlin last year.

'Their purchase continues the significant investment we have made in the park since we took over seven years ago. Dinomite, which opened two years ago, cost £1.5m and we have spent more than £2.5m in total.'

The investment had seen visitor numbers increase 40pc in that time and they were expecting 200,000 visitors this year.

He emphasised that the existing dinosaur collection would remain by popular demand.

'We have a lot of loyal followers, with 10,000 season ticket holders, and a lot of the existing dinosaurs are firm favourites,' he said.

Mr Goymour, whose son Adam is park manager, said their five-year plan would see even more exciting developments. 'We have plans for a live dino theatre experience and possibly a 3D cinema showing short dinosaur films,' he said. 'We are also looking at the possibility of an outdoor splash zone with fountains.'

While the animatronic dinosaurs are restricted to their stands – the T-Rex will have Jurassic Park-style fencing built around it – visitors are likely to come face to face with a dinosaur roaming the park by the end of the summer.

For the park's dinosaur sculptor is working on a raptor which will be brought to life by an operator inside it.