WHEN it comes to dinosaurs, Dr Steve Brusatte of Edinburgh University has a list of qualifications as long as the tail on a diplodocus.

Yet even he finds himself regularly impressed by the number of five-year-olds he meets who can name lots of dinosaurs and pronounce their names perfectly.

"They just amaze me," says the Chancellor's Fellow in Vertebrate Palaeontology.

All those with a T-Rex like appetite for these awesome beasts will want to book now for Walking With Dinosaurs, a new 3D movie out next week. Using special effects from the teams behind the likes of Avatar and Legend of the Guardians, Walking with Dinosaurs takes audiences back to what is now Alaska in the late Cretaceous period.

Neil Nightingale, one of the film's two directors and the creative director of BBC Earth, promises junior experts and absolute beginners alike "the most amazing dinosaur experience of all time".

Dr Brusatte, one of a team of scientific and technical consultants on the film, says: "It has been 20 years since Jurassic Park came out. We've learned a lot about dinosaurs since then and movie-making technology has evolved a lot."

Inspired by the BBC television series that first aired in 1999, Walking with Dinosaurs tells the story of Patchi, a pachyrhinosaurus, from egg to adulthood, as he navigates the perils and joys of life 70 million years ago. Besides Justin Long, who voices Patchi, the cast includes Ice Age favourite John "Sid the Sloth" Leguizamo, here playing a prehistoric bird.

Brusatte, a 29-year-old American who moved to Scotland in February, first became involved with the production when he was asked to be a consultant on the website linked to the film. From there his role expanded, with one of his jobs being to check that the way the dinosaurs were moving in the accompanying video game, for example, was correct. "That they weren't shown moving too fast or too slow, that the different dinosaurs living together actually did live together, those kind of things."

Over the years he has seen some dinosaur-related howlers. Common mistakes include dinosaurs dragging their tales, or moving at speeds which were impossible. In 1993's Jurassic Park, for instance, a T-Rex is showing chasing a car going at high speed. "We now know that couldn't happen," says Brusatte. Another post-Jurassic Park development audiences will see in the new movie are dinosaurs with feathers.

What has never been in doubt is the enduring fascination youngsters have for dinosaurs. Nightingale puts this down to them being terrifying, but also extinct. "They are monsters but they are not around to come and eat you, so you can be scared by them, impressed by them, but they are not going to jump out from behind the bed and grab you."

Brusatte joined the club when he was a teenager living in the mid-West and helping his younger brother with a science project. "His room was like a dinosaur museum." Brusatte was soon hooked. "It just swept over me."

Ask him to name his favourite dinosaur and he laughs, comparing it to being asked to choose a favourite child. If pushed, though, he admits to a soft spot for T-Rex.

"This thing was just an almost mythical killing machine. [It was] an amazing feat of evolution to have something that was 13 metres long, five or six tons and could bite through a car."

There is a simply a magic about dinosaurs, he reckons. "Dinosaurs are more fantastic than a lot of things humans have invented - unicorns and leprechauns and dragons and all kinds of monsters out of mythology and fable. Dinosaurs were real, they were living, breathing animals."

Brusatte believes the picture "does a really good job of blending a good story with good science." But in giving voice to the dinosaurs, is it not in danger of anthropomorphising them?

"The voiceovers are a bit of a compromise; the dinosaurs' lips aren't moving, they are not smiling and having human-like facial expressions or anything like that," says Brusatte. "They are only anthropomorphised to a small degree and that is necessary for a film like this." It is, he says, scientifically inspired entertainment, not a science documentary.

Indeed, what impressed Brusatte was the film-makers' determination to get the science right. "Neil and the others went to scientists, talked to them, they read a lot about the latest discoveries and they used so much of this information that we've learned over the past few decades, about feathered dinosaurs, about how dinosaurs lived in big herds, which dinosaurs preyed on each other, their environments, and used that to tell the story. The science comes across very, very well in the film."

As co-director, it was Nightingale's job to put this knowledge on the screen in a convincing and thrilling way. To do that, he and co-director Barry Cook journeyed with a team to Alaska and New Zealand to film real landscapes that were later married to computer-generated dinosaurs. At the time when the story is set, the climate in the Arctic was much warmer, explains Nightingale, rather like Scotland's today, though there was 24-hour darkness in the winter and constant sunshine in the summer.

The scouting team did not just have to find spectacular locations, they had to pinpoint ones that fitted the story exactly. Even then, the "stars", the dinosaurs, were missing. To make sure the scene would work when they got home, and despite all the cutting-edge technology deployed for the film, some low-tech techniques were deployed.

"We built life-size dinosaurs out of drain pipes which gave us at least the scale of them in the landscape, and then we would walk them or run them through the shot," says Nightingale. Once back in the UK, they combined the elements. "It was just magic, a wonderful moment seeing those two worlds coming together."

Brusatte has been on something of a climatological learning curve since arriving in Scotland. He and his wife are "loving it here", he says. "The very short days at this time of year have taken a little bit to adjust to but otherwise it's nice. The winters are a lot warmer than what I'm used to in Chicago."

One of his tasks at Edinburgh is setting up a new research group. It is a great time to be involved in this field, he says. "Paleontology really is our only evidence of how actual organisms and ecosystems have changed over time, how they have changed with changing climates, sudden episodes of warming, or a big volcanic eruption or impact." And our knowledge of dinosaurs remains at a very early stage. "Really it is still just the tip of the iceberg. If another film is done 20 years from now I can only imagine what other cool new things we might be able to put in there."

Nightingale, too, hopes Walking with Dinosaurs is just the start of great, dinosaur-sized things to come. If he has one wish for the film, he says, it is that it will inspire a life-long interest in dinosaurs among young audiences.

"Maybe some people will even become palaeontologists."

Walking with Dinosaurs: The 3D Movie opens on December 20