The Hylidae are a wide-ranging family of frogs commonly referred to as 'tree frogs and their allies'. However, the hylids include a diversity of frog species, many of which do not live in trees, but are terrestrial or semiaquatic. The earliest known fossils that can be assigned to this family are from the Cretaceous of India and the state of Wyoming in the United States. Most hylids show adaptations suitable for an arboreal lifestyle, including forward-facing eyes providing binocular vision, and adhesive pads on the fingers and toes. In the nonarboreal species, these features may be greatly reduced, or absent. The Cyclorana species are burrowing frogs that spend much of their lives underground.