In many ways this is a retrospective. Walking With Dinosaurs came out almost 12 years ago, in 1999. Last century stuff. But it set the stage for all the dino-documentaries that have come out since.

When it came out, realistic computer-generated dinosaurs were certainly a possibility in movies – Jurassic Park preceded and partly inspired Walking With Dinosaurs. But managing this quality of CGI on a television budget, treating the whole thing as a documentary and bringing in paleontologists not only as advisors but at times as collaborators, was new.

I do have some quibbles with the six episodes. First, there are a few places where the narration is just plain wrong. I’m not talking about things that were learned after the film was made or guesses that are presented as fact; I’m talking about things like the statement that carbon monoxide is heavier than air. In fact, it is almost exactly the same density as air. The suffocating, low-lying gas that is produced by volcanic action, and is heavier than air, is carbon dioxide.

Second, there are many things in the DVD that are pure guesswork. Some of these are pretty obvious, like the colors of extinct animals. No real problem there — they had to be some color, after all, and why not pattern them after existing reptiles? In some cases, such as pterosaurs getting around on the ground, even the paleontologists learned something from the animators’ efforts to get the animals to move. But flat statements such as the one that cynodonts paired for life, for instance, seem sheer guesswork.

Finally, this DVD has to be watched with recognition that a great deal has been learned about dinosaurs in the last 12 years. We now know, for instance, that a great many of the predatory dinosaurs had feathers, probably both for insulation and for display. Our ideas about the social life of dinosaurs are also undergoing a transition. The DVD shows Tyrannosaurs as solitary animals, guarding their territories jealously. There is increasing evidence that they may have hunted in packs, with a social life more like wolves.

Do look at the second DVD, the one that has “The making of” sequence. This points out things that are all too often ignored in later dino-documentaries, such as the fact that grass evolved quite recently, and was never present when the non-avian dinosaurs were alive.

This was the first made of the “trilogy of life” series, though it is the middle one in terms of geologic time. This trilogy is still probably the best of the dino-documentaries.