Skip the American version and buy the Brit original

I taped the American version when it aired on ANIMAL PLANET. I decided the CGI sequences were nifty enough to justify ordering the DVD. When the DVD arrived, I was surprised to see it was radically different. The biggest difference was wraparound drama detailing the quest of fictional paleontologist Jack Tanner (Paul Hilton) to deuce the nature of dragons based on a fossilized T-Rex and an intact cadaver in a Balkan ice cave.
Tanner and his associates are given the briefest view in the A-P version.

The other difference was the narration. In the A-P version, Patrick Stewart gives a "dummy's guide" version, quickly spelling out the various "facts" of dragon biology. The original version is more suspenseful, as we learn each fact as Dr. Tanner figures it out.

Of course, there's other reasons to watch the DVD-- Freeze frames! Zooms! Screen caps! And a better sound track.