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, Phyllomedusidae and Pelodryadinae.
The following genera are recognised in the family Hylidae:
- Tribe Cophomantini
- Aplastodiscus – canebrake treefrogs
- Boana – gladiator treefrogs
- Bokermannohyla
- Hyloscirtus
- Myersiohyla
- Nesorohyla
- "Hyla" nicefori
- Tribe Dendropsophini
- Dendropsophus
- 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
- Tribe Pseudini
- Lysapsus – harlequin frogs
- Pseudis – swimming frogs
- Scarthyla – Madre de Dios tree frogs
- Tribe Scinaxini
- Julianus
- Ololygon (synonymous with Scinax)
- Scinax – snouted tree frogs
- Tribe Sphaenorhynchini
- Sphaenorhynchus – lime tree frogs
- Incertae sedis
- "Hyla" imitator – mimic tree frog
The subfamilies Pelodryadinae and Phyllomedusinae are sometimes classified as subfamilies of Hylidae, but due to their deep divergence and unique evolutionary history are increasingly considered separate (with Pelodryadidae being the sister group to Phyllomedusidae and colonizing Australia during the Eocene via the Antarctic land bridge, which at the time was not yet frozen over).
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, these features may be greatly reduced, or absent.
Distribution and habitat
The European tree frog (Hyla arborea) is common in the middle and south of Europe, and its range extends into Asia and North Africa.
North America has many species of the family Hylidae, including the gray tree frog (Hyla versicolor) and the American green tree frog (H. cinerea). The spring peeper (Pseudacris crucifer) is also widespread in the eastern United States and is commonly heard on spring and summer evenings.
Behaviour and ecology
Species of the genus Cyclorana are burrowing frogs that spend much of their lives underground.
Breeding
Hylids lay their eggs in a range of different locations, depending on species. Many use ponds, or puddles that collect in the holes of their trees, while others use bromeliads or other water-holding plants. Other species lay their eggs on the leaves of vegetation hanging over water, allowing the tadpoles to drop into the pond when they hatch.