Walking with Dinosaurs is a six-part documentary television miniseries created by Tim Haines and produced by BBC Natural History Unit. The series first aired on the BBC in the United Kingdom in 1999 with narration by Kenneth Branagh. The series was subsequently aired in North America on the Discovery Channel in 2000, with Avery Brooks replacing Branagh. The program explores ancient life of the Mesozoic Era, portraying dinosaurs and their contemporaries in the style of a traditional nature documentary. Developed by Haines and producer Jasper James, Walking with Dinosaurs recreated extinct species through the combined use of computer-generated imagery and animatronics that were incorporated with live action footage shot at various locations. The Guinness Book of World Records reported that the series was the most expensive documentary series per minute ever produced. A re-edited version of Walking with Dinosaurs aired on Discovery Kids for the first season of Prehistoric Planet. It was made more appropriate for children by removing most of the graphic content and trimming down some footage to fit the run time.