What is the ancestor of the Gila monster?

The Gila monster (Heloderma suspectum) is a member of the family Helodermatidae, which diverged from other reptiles around 100 million years ago. Its ancestors are believed to be related to ancient lizards, specifically the group known as squamates. The lineage that led to Gila monsters adapted to a burrowing lifestyle, which is reflected in their morphology and behavior. Overall, their evolutionary history is tied to the broader diversification of lizards during the Cretaceous period.