I think he means that he wants to create a blend of real-life and computer graphics - ever seen Walking With Dinosaurs? Something like that.

3DGS isn't really the right program, as it's for games. You certainly could do something like machinima - make a dinosaur game and then use FRAPS or something to record scenes like a director, and stitch them together. But if you want to do it like the pros, you'd need something like Blender or 3DSMax, and some way of integrating that footage with real-life footage.
Have a look at this site:
http://www.peerlessproductions.com/
And have a look at his 'visual effects' page. Lots of examples of integrating computer graphics with real-life footage - and very impressive ones at that. He also has a tutorial on using Icarus for tracking, which should be useful.
eHy, I might have a look at that...