If you enjoyed this movie, you are almost sure to enjoy the series of novels written by Lin Carter, the Zanthodon series, which Carter wrote as a modern pastiche of Edgar Rice Burroughs Pellucidar series.
The first novel was Journey To the Underground World (1979), it was followed by 4 sequels. Prehistoric thrills and spills in a world buried deep in the Earth's crust!
Everything will be OK in the end, if it aint OK,it aint the end.
I thoroughly enjoyed Zanthodon. It inspired me to try my hand at a lost world story of my own.* The five Zanthodon books would also make a fine series of movies.
And if Journey to the Underground World was at all successful somebody would remake At The Earth's Core. And then all the JttUW movie fans would scream, "At The Earth's Core is a RIPOFF of Journey to the Underground World! How DARE they!?! What's next, pirates?!!?!!?!"
Um, yes. Pellucidar had pirates before Zanthodon was ever thought of.
I disagree with you, but I'm pretty sure you're not Hitler.
- Jon Stewart
* Of course, it can't be a successful series of books if I never write more than the Forward and bits and pieces of various chapters, which is how far I've gotten and likely as far as I will ever get. But hey, it's fun. My main character is an army Ranger turned hippie who meets a time traveling professor at Woodstock and... never mind.