The postcranial skeleton of Lanthanotus borneensis is described and compared to that of Heloderma and Varanus. In an evolutionary sense, Lathanotus is intermediate in structure between Heloderma showing relatively primitive and Varanus showing relatively advanced character states. This conclusion is well supported by the structure of the tarsus. Cladistically, Lanthanotus is the sister-taxon of Varanus, the two lineages together forming the sister-taxon of Heloderma, a conclusion based on the distribution of shared derived characters.