Mixing fact with speculation: Tom Hagler reports

But Walking With Dinosaurs has also clearly irked some scientists who believe it reflects a worrying trend towards popularising science at the expense of the facts - a state of affairs which, they argue, could eventually undermine science in the eyes of the public.

The programmes use cutting-edge computer animation and animatronics to show how the creatures might have looked when they walked the Earth at least 65 million years ago.

The quality of many of the fossil specimens in world museums means we have a very good idea of how some of these creatures looked, but we actually have precious little information about how they behaved - no-one knows, for example, how male-female pairs would have conducted courtship and mating.

Watch the opening sequence of the first episode

And yet, in the great tradition of natural history television, this is precisely what we are presented with in Walking With Dinosaurs.

"The dinosaurs only exist as fossils," says series producer Tim Haines. "We know a great deal about them but we don't actually know enough to have them running around as we do in our programmes. We have to use informed speculation to fill in the gaps."

Greater realism

But the critics argue that Walking With Dinosaurs should have made a bigger effort to tell the audience where the facts finished and the speculation started.

"When you fill in the gaps you come down to individual judgements and they have shown things I wouldn't necessarily agree with," says Dr Paul Upchurch, a palaeontologist at Cambridge University.

The giant Ornithocheirus is shown calling to a mate

"One programme showed an animal guarding a territory and other animals were said to be bonding for life. I appreciate that this gives the natural history feel of the programme a greater realism but it is not something we can defend scientifically."

Dr Graham Farmelo from London's Science Museum concedes that it would have been tedious to qualify every statement with "we think that" or "we suspect that".

"On the other hand," he says, "there are very important distinctions to be made between things we are practically certain of and things which might possibly be true - and I think the series doesn't address these issues nearly seriously enough."

Black and white

The media as a whole is often accused of trivialising scientific debate by portraying complex issues in simplistic black and white terms. The pace of scientific development can sometimes seem bewildering and the facts can all too easily be lost in the requirement for instant opinions.

This makes it all the harder for society to take the important decisions about the application of new science, warns Dr Farmelo.

Tim Haines and Paul Upchurch discuss the science in Walking With Dinosaurs

"Science and technology are throwing up issues that impinge directly on people's lives. There are so many examples, such as how we feel about genetically-modified (GM) foods. It is important that scientists have a dialogue with the public to make sure that the debate is informed - because there is a lot of reflex opinion-forming that I think is very dangerous."

Science has thrown up an array of media stars in the last few years. These are men and women whose books regularly hit the top of the best seller lists and have a knack for making even the most difficult concepts seem accessible.

It is what science should be about, says one of the very best of them, Steve Jones, Professor of Genetics at University College London.

"It's often forgotten, for example, that when Darwin wrote the Origin of Species in 1859 he wrote it as a popular science book - it wasn't a technical book for biologists.