The show premiered in the United States in the fall of 1999 (after the TV-movie/pilot aired in February on DirecTV and then on the cable television channel TNT in April).

The group, some mismatched enthusiasts with less than selfless reasons for making the journey, consists of Challenger, Professor Arthur Summerlee, Marguerite Krux, Major Lord John Richard Roxton and Edward T. Malone.

The group is assisted by a young jungle-savvy woman named Veronica Layton, whose parents disappeared eleven years before.

Together, the group fights to survive against carnivorous dinosaurs, vicious Neanderthals, a race of lizard men, and other perils as they search for a way to escape.

Roxton's role as Marguerite's modern day knight originates with his childhood and ancestral home having close proximity to Avebury, nearly twenty miles from Stonehenge.

[2] The series would have been resolved with Malone and Veronica together as a couple and staying in Avalon, while Challenger uses his teleportation invention from the episode "Finn" to send himself, Roxton, Marguerite, and Summerlee to London, but travels forward in time to the year 2005 where they are warmly greeted by the zoological society due to Malone having sent them a letter explaining when they would arrive.

The fourth season would have featured guest appearances of two other Arthur Conan Doyle characters, Sherlock Holmes and Professor James Moriarty.

[12][13] The series continued to be rerun in daily strip form in the United States on the Time Warner owned TNT in the early morning hours Monday through Friday.

The original 93 minute version pilot movie was released on DVD in 4:3 PAL under the title, The Lost World The Beginning by ILC Prime licensed by Fremantle Corporation.