Walking with Dinosaurs was a six-part documentary television mini-series that was produced by the BBC, narrated by Kenneth Branagh, and first aired in the UK in 1999. The series was subsequently aired in North America on the Discovery Channel in 2000, with Branagh's voice replaced with that of Avery Brooks. It is the first entry of the Walking with... series and used computer-generated imagery and animatronics to recreate the life of the Mesozoic, showing dinosaurs in a way that previously had only been seen in feature films. The program's aim was to simulate the style of a nature documentary and therefore does not include "talking head" interviews. The series used paleontologists such as Peter Dodson, Peter Larson and James Farlow as advisors (their influence in the filming process can be seen in the documentary Walking with Dinosaurs - The Making Of). The Guinness Book of World Records reported that the series was the most expensive documentary series per minute ever made.