He pictures the lost continent of Lemuria as a prehistoric kingdom located in the Pacific Ocean during the Ice Age, where Mesozoic wildlife persisted after the cataclysm wiped them out elsewhere.

An intelligent reptilian humanoid race descended from dinosaur reigned supreme as the dominant life form but was partially supplanted by humanity as the continent was colonized by fauna from outside Lemuria.

Culturally, Lemuria is a mixture of civilization and barbarism but overall is precociously advanced over the outside world, boasting a magic-based technology that includes even flying machines.

The Thongor books relate the struggle of the titular hero to unite the humans of Lemuria into a single empire and complete the overthrow of the "dragon kings".

After Carter was recruited by L. Sprague de Camp to assist in continuing Howard's original Conan series, however, his interest in Thongor waned.

As of September 2016, author and long-time friend of Lin Carter Dr. Robert M. Price released a collected edition of original Thongor stories with an introduction by Richard A.