The Times (London), November 12 1999

Michael J. Benton, a palaeontologist, takes issue with antediluvian critics who sank teeth into the series

Why I dared walk with TV dinosaurs

THE series is over. The last tyrannosaurus has lurched off into the blood-red sunset. Triceratops has breathed its last in the poisonous atmosphere of the late Cretaceous. Was Walking with Dinosaurs the biggest science documentary yet, or was it no more than media gimcrackery?

I was involved in the series from its early days, as palaeontological consultant for the first programme. Several of my colleagues from Bristol were also involved: David Unwin, Donald Henderson and Jo Wright.

Did we sell our souls? Yes, according to some. We have been accused by a fellow palaeontologist of being seduced by the bright lights, of selling our expertise cheaply. He called us prostitutes on an e-mail discussion list. His message reached thousands of professional palaeontologists around the world.

This has created an unusual situation since most of these overseas palaeontologists have not yet seen the series, and may imagine it tawdry and cringe-making.

The critics have adopted a number of poses. One or two have been outright in their condemnation. They have equated WWD with the Godzilla movies, arguing that the animations are amateurish and the realism spurious. Their claim has been that Godzilla is presented as knockabout fun, which is fine, but WWD was shown as a pseudo-nature documentary, and so it will mislead the public horribly.

The second category of critic, typified by Dr Henry Gee, a palaeontologist and an editor with Nature magazine, has not condemned the series outright. In his review, however, he complained about the formulaic story lines, the mix of fact and speculation, the leaden script.

We are left with a lingering feeling that what WWD really needed was a serious hand at the tiller to lend it some authority. Or perhaps it should never have been attempted. The cynic is not obliged to be specific, merely to smile indulgently at the caperings of his fellow human beings, while muttering, "Tut, tut". The third category of WWD-haters, the fact-checkers, began compiling lists of errors in the first week. These were gleefully circulated on the e-mail lists. For example, in the first programme postosuchus urinates copiously. This was a moment that my children relished. But birds and crocodiles, the closest living relatives of the dinosaurs, do not urinate. They shed their waste as more solid uric acid. Someone should have spotted this, and I include myself.

Another purported error, or at least "can't be sure", was that the little cynodonts are said to have pair-bonded for life. We can never know this from the fossil bones - not an error, since it's possible, if not even likely, but a claim too far. Then, the fact-checkers rather ran out of steam. They have not said so, but they have not actually found too many errors. They have found to their surprise that the BBC consulted 100 palaeontologists in various countries, and has been careful about accuracy.

The main issue of concern is the mix of fact and fantasy in the series. What is known is fact, and what is not known is termed fantasy or speculation. But those are pejorative terms, and it is worth disentangling the difference between fact and fiction in palaeontology.

There are levels of certainty. The fossil skeletons show the shape and size of a dinosaur, its provenance shows where it lived, what the climate was, and with whom it associated. These can be termed facts.

But what of the fantasy? Well, much of the speculation I would term strong supposition. For example, the bones show where the muscles went and how large they were. This gives the overall body shape. The teeth show what the animal ate, and the jaw shape shows how it fed. The limb bones show how the dinosaurs moved. You can manipulate the joints and calculate the movements, stresses and strains of the limbs. It is poss-ible to work out the pattern of locomotion in great detail.

All the walking, running, swimming and flying shown in WWD was based on immensely careful calculation and modelling. Fantasy? Speculation? No. I would suggest that all these behaviours are 80 per cent accurate, or better.

The third level of certainty includes everything else: the colours and patterns, the breeding habits, the noises. However, even these, although entirely unsupported by fossil data, are not fantasy. Palaeobiologists base their speculations here on comparisons with living animals. What colour was diplodocus? It was a huge plant-eater. Modern huge plant-eaters, such as elephants and rhinos, have thick, grey, wrinkly skin. So we gave diplodocus thick, grey, wrinkly skin. The cynodonts in the first programme are close relatives of the ancestors of mammals. Most modern mammals pair-bond for life and all suckle their young. Perhaps it is reasonable to transfer such behaviour to the fossil form?

People with only a hazy notion of palaeontology can surely work this out. Who would seriously imagine that fossils can show skin colour or breeding behaviour?I challenged the critics to say how they would distinguish among the levels of certainty. Perhaps the film-makers should have blown a puff of smoke across the screen when some speculative behaviour was shown?

Or, perhaps, the head of a distinguished palaeontologist should appear in the top right corner and say: "Well, we don't really know whether they copulated in that way. But . . ."

Neither would have worked. Both ploys would destroy the illusion.

Was WWD merely a media event? The first programme was rated 19th most popular on the BBC, beaten only by royal weddings, cup finals, and EastEnders. It was promoted last week as an example of the output of the new BBC, not concerned with ratings (of course), but seeking to innovate and lead the world.

Palaeontologists should rejoice. However, there is still the lingering issue; did media values come before scientific values? Was there a compromise to improve viewing figures and recoup the millions spent? I see WWD as a natural progression, both in the promotion of the public understanding of science and in the reconstruction of past life. From the time of the discovery of the first dinosaurs in the 1820s, palaeontologists have published popular accounts and illustrations.

In 1854 Waterhouse Hawkins's models of dinosaurs were unveiled at Crystal Palace. These were lifesize sculptures in concrete form and painted garishly. There were no complaints of trivialisation. Now we have moving pictures and computers, it is absolutely right to bring them into service as scientific tools. Science is about taking risks, about making informed speculations. It's safest for a scientist not to speculate, but it's only the speculators - Newton, Darwin, Einstein - who made a mark.

Michael Benton is Professor of Vertebrate Palaeontology at the University of Bristol. His Vertebrate Palaeontology will be reissued by Blackwell Science in January.

Bristol University Earth Department