 The family Varanidae probably originated in Asia about 65 million years ago, although some estimates are as early as the late Mesozoic (112 million years ago).Monitor lizards probably migrated to Australia and the Indonesian archipelago between 39 and 26 million years ago.All members of the "V. prasinus" species group (sometimes referred to as subgenus "Euprepiosaurus") are found east of Lydekker’s line in the Indo-Australian Archipelago.