Hylidae is 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. Taxonomy and systematics 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. The common name of "tree frog" is a popular name for several species of the family Hylidae. However, the name "treefrog" is not unique to this family, also being used for many species in the family Rhacophoridae. The following genera are recognised in the family Hylidae: Subfamily Hylinae Tribe Cophomantini Aplastodiscus – canebrake treefrogs Boana – gladiator treefrogs Bokermannohyla Hyloscirtus Myersiohyla Nesorohyla "Hyla" nicefori Tribe Dendropsophini Dendropsophus Julianus Lysapsus – harlequin frogs Ololygon (synonymous with Scinax) Pseudis – swimming frogs Scarthyla – Madre de Dios tree frogs Scinax – snouted tree frogs Sphaenorhynchus – lime tree frogs Xenohyla Tribe Hylini Acris – cricket frogs Atlantihyla Bromeliohyla Charadrahyla Dryophytes – Ameroasian treefrogs Duellmanohyla – brook frogs Ecnomiohyla Exerodonta Hyla – common tree frogs Isthmohyla Megastomatohyla Plectrohyla – spike-thumb frogs Pseudacris – chorus frogs Ptychohyla – stream frogs Quilticohyla Rheohyla – small-eared treefrog Sarcohyla Smilisca – burrowing frogs Tlalocohyla Triprion – shovel-headed tree frogs Tribe Lophiohylini Aparasphenodon – casque-headed frogs Argenteohyla – Argentinian frogs Corythomantis – casque-headed tree frog Dryaderces Itapotihyla Nyctimantis – brown-eyed tree frogs Osteocephalus – slender-legged tree frogs Osteopilus Phyllodytes – heart-tongued frogs Phytotriades – Trinidad golden treefrogs Tepuihyla – Amazon tree frogs Trachycephalus – casque-headed tree frog Incertae sedis "Hyla" imitator – mimic tree frog Subfamily Pelodryadinae (Australian tree frogs) Litoria Nyctimystes Ranoidea Incertae sedis "Litoria" castanea "Litoria" jeudii "Litoria" louisiadensis "Litoria" obtusirostris "Litoria" vagabunda Subfamily Phyllomedusinae (leaf frogs) Agalychnis Callimedusa Cruziohyla Hylomantis – rough leaf frogs Phasmahyla – shining leaf frogs Phrynomedusa – colored leaf frogs Phyllomedusa PithecopusThe subfamilies Pelodryadinae and Phyllomedusinae are sometimes classified as distinct families of their own due to their deep divergence and unique evolutionary history (with Pelodryadinae being the sister group to Phyllomedusinae and colonizing Australia during the Eocene via Antarctica, which at the time was not yet frozen over), but are presently retained in the Hylidae. Description 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,