The Microhylidae, commonly known as narrow-mouthed frogs, are a geographically widespread family of

frog A frog is any member of a diverse and largely carnivorous group of short-bodied, tailless amphibians composing the order Anura (ανοὐρά, literally ''without tail'' in Ancient Greek). The oldest fossil "proto-frog" ''Triadobatrachus'' is ...

s. The 683 species are in 63 genera and 11 subfamilies, which is the largest number of genera of any frog family.

Evolution

A molecular phylogenetic study by van der Meijden, et al. (2007) has estimated the initial internal divergence of the family Microhylidae to have taken place about 66 million years ago, or immediately after the Cretaceous extinction event. The most recent common ancestor of the Microhylidae and their closest ranoid relatives is estimated to have lived 116 million years ago in Gondwana.

Description

As suggested by their name, microhylids are mostly small frogs. Many species are below in length, although some species are as large as . They can be

arboreal Arboreal locomotion is the locomotion of animals in trees. In habitats in which trees are present, animals have evolved to move in them. Some animals may scale trees only occasionally, but others are exclusively arboreal. The habitats pose nu ...

or terrestrial, and some even live close to water. The ground-dwellers are often found under leaf litter within forests, occasionally venturing out at night to hunt. The two main shapes for the microhylids are wide bodies and narrow mouths and normal frog proportions. Those with narrow mouths generally eat

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s and

ant Ants are eusocial insects of the family Formicidae and, along with the related wasps and bees, belong to the order Hymenoptera. Ants evolved from vespoid wasp ancestors in the Cretaceous period. More than 13,800 of an estimated total of 22,0 ...

s, and the others have diets typical of most frogs. Egg-laying habits are highly varied.

Reproduction

The microhylids of New Guinea and Australia completely bypass the tadpole stage, with direct development from

egg An egg is an organic vessel grown by an animal to carry a possibly fertilized egg cell (a zygote) and to incubate from it an embryo within the egg until the embryo has become an animal fetus that can survive on its own, at which point the a ...

to frog. The arboreal species can therefore lay the eggs within the trees, and never need venture to the ground. Where species do have tadpoles, these almost always lack the teeth or horny beaks typical of the tadpoles of other families.

Anatomy

The skull has paired

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and frontoparietals. The facial nerve passes through the anterior acoustic foramen in the auditory capsule; the trigeminal and facial nerve ganglia are fused to form a prootic ganglion. The eight (or seven) presacral holochordal vertebrae are all procoelous except for a biconcave surface on last presacral. The pectoral girdle is firmisternal and some show reduced clavicle and procoracoids. The terminal phalanges are blunt, pointed, or T-shaped. The tadpole lacks keratinized mouth parts and has a large spiracular chamber emptied by a caudomedial spiracle.

Taxonomy

* subfamily Adelastinae Peloso, Frost, Richards, Rodrigues, Donnellan, Matsui, Raxworthy, Biju, Lemmon, Lemmon, & Wheeler, 2015 ** genus '' Adelastes'' Zweifel, 1986 * subfamily

Asterophryinae Asterophryinae is a subfamily of microhylid frogs distributed in an area from the Peninsular Malaysia through the Malay Archipelago to northern Australia. Genera The following genera are recognised in the subfamily Asterophryinae: The most spec ...

Günther, 1858 ** genus '' Aphantophryne'' Fry, 1917 ** genus '' Asterophrys'' Tschudi, 1838 ** genus '' Austrochaperina'' Fry, 1912 ** genus '' Barygenys'' Parker, 1936 ** genus '' Callulops'' Boulenger, 1888 ** genus '' Choerophryne'' Van Kampen, 1914 ** genus ''

Cophixalus ''Cophixalus'' (rainforest frogs or nursery frogs) is a genus of microhylid frogs. These are arboreal species with expanded toe-pads, endemic to Moluccan Islands, New Guinea and northeastern Queensland, Australia. Species As of December 2019, A ...

'' Boettger, 1892 ** genus ''

Copiula ''Copiula'' is a genus of microhylid frogs endemic to New Guinea. The common name Mehely frogs has been coined for them. They are leaf-litter inhabitants. Taxonomy ''Copiula'' is probably not monophyletic. Some former ''Austrochaperina'' species ...

'' Méhely, 1901 ** genus '' Gastrophrynoides'' Noble, 1926 ** genus '' Hylophorbus'' Macleay, 1878 ** genus '' Mantophryne'' Boulenger, 1897 ** genus '' Oninia'' Günther, Stelbrink & von Rintelen, 2010 ** genus '' Oreophryne'' Boettger, 1895 ** genus ''

Paedophryne ''Paedophryne'' (from the Ancient Greek ''paedos'' (παίδος) "child" and ''phryne'' (φρύνος) "toad, frog") is a genus of microhylid frogs from Papua New Guinea, including D'Entrecasteaux Islands. All seven species known so far are a ...

'' Kraus, 2010 ** genus ''

Siamophryne ''Siamophryne'' is a genus of frog found in Thailand. It is monotypic, consisting of only one species, the Tenasserim cave frog (''Siamophryne troglodytes''). Its closest relative is the genus '' Vietnamophryne''. The genus ''Siamophryne'' was ...

'' Suwannapoom, Sumontha, Tunprasert, Ruangsuwan, Pawangkhanant, Korost, and Poyarkov, 2018 ** genus ''

Sphenophryne ''Sphenophryne'' is a genus of frogs in the family Microhylidae from New Guinea. It reached its current composition in 2017 when Rivera and colleagues brought the genera ''Genyophryne'', ''Liophryne'', and ''Oxydactyla'' into synonymy of the the ...

'' Peters & Doria, 1878 ** genus ''

Vietnamophryne ''Vietnamophryne'' (common name: Indochinese dwarf frogs; Vietnamese: ''nhái lùn''; Thai: ''ueng tham khrae'', ) is a divergent genus of Asterophryinae frogs found in Indochina. Its closest relative is the genus ''Siamophryne''. The genus ''Vi ...

'' Poyarkov, Suwannapoom, Pawangkhanant, Aksornneam, Duong, Korost and Che, 2018 ** genus ''

Xenorhina ''Xenorhina'' is a genus of microhylid frogs. The genus is endemic to New Guinea New Guinea (; Hiri Motu: ''Niu Gini''; id, Papua, or , historically ) is the world's second-largest island with an area of . Located in Oceania in the sout ...

'' Peters, 1863 * subfamily Chaperininae Peloso, Frost, Richards, Rodrigues, Donnellan, Matsui, Raxworthy, Biju, Lemmon, Lemmon, & Wheeler, 2015 ** genus '' Chaperina'' Mocquard, 1892 * subfamily

Cophylinae Cophylinae is a subfamily of microhylid frogs endemic to Madagascar. It has over 100 species in eight genera. Members of this subfamily range from minute ( 100 mm adult body size), and they are highly ecologically diverse. DNA barcode resear ...

Cope, 1889 ** genus '' Anilany'' Scherz, Vences, Rakotoarison, Andreone, Köhler, Glaw, and Crottini, 2016 ** genus '' Anodonthyla'' Müller, 1892 ** genus ''

Cophyla ''Cophyla'' is a genus of microhylid frogs endemic to Madagascar Madagascar (; mg, Madagasikara, ), officially the Republic of Madagascar ( mg, Repoblikan'i Madagasikara, links=no, ; french: République de Madagascar), is an island coun ...

'' Boettger, 1880 ** genus '' Madecassophryne'' Guibé, 1974 ** genus ''

Mini The Mini is a small, two-door, four-seat car, developed as ADO15, and produced by the British Motor Corporation (BMC) and its successors, from 1959 through 2000. Minus a brief hiatus, original Minis were built for four decades and sold during ...

'' Scherz, Hutter, Rakotoarison, Riemann, Rödel, Ndriantsoa, Glos, Roberts, Crottini, Vences & Glaw, 2019 ** genus '' Plethodontohyla'' Boulenger, 1882 ** genus '' Rhombophryne'' Boettger, 1880 ** genus '' Stumpffia'' Botteger, 1881 * subfamily Dyscophinae Boulenger, 1882 ** genus '' Dyscophus'' Grandidier, 1872 * subfamily Gastrophryninae Fitzinger, 1843 ** genus '' Arcovomer'' Carvalho, 1954 ** genus '' Chiasmocleis'' Méhely, 1904 ** genus '' Ctenophryne'' Mocquard, 1904 ** genus '' Dasypops'' Miranda-Ribeiro, 1924 ** genus '' Dermatonotus'' Méhely, 1904 ** genus '' Elachistocleis'' Parker, 1927 ** genus ''

Gastrophryne ''Gastrophryne'', the narrowmouth toads (also American narrowmouth toads, North American narrow-mouthed toads), is a genus of microhylid frogs found in the Americas between Honduras and southern United States. Its name means ‘belly-toad’, r ...

'' Fitzinger, 1843 ** genus '' Hamptophryne'' Carvalho, 1954 ** genus '' Hypopachus'' Keferstein, 1867 ** genus '' Myersiella'' Carvalho, 1954 ** genus '' Stereocyclops'' Cope, 1870 * subfamily Hoplophryninae Noble, 1931 ** genus '' Hoplophryne'' Barbour & Loveridge, 1928 ** genus '' Parhoplophryne'' Barbour & Loveridge, 1928 * subfamily Kalophryninae Mivart, 1869 ** genus '' Kalophrynus'' Tschudi, 1838 * subfamily

Melanobatrachinae ''Melanobatrachus'' is a genus of narrow-mouthed frogs in the family Microhylidae. It is the only remaining genus in the monotypic subfamily Melanobatrachinae. It contains a single species, ''Melanobatrachus indicus'', also known as the Indian ...

Noble, 1931 ** genus '' Melanobatrachus'' Beddome, 1878 * subfamily Microhylinae Günther, 1858 ** genus '' Glyphoglossus'' Gunther, 1869 "1868" ** genus '' Kaloula'' Gray, 1831 ** genus '' Metaphrynella'' Parker, 1934 ** genus ''

Microhyla ''Microhyla'', commonly known as the rice frogs or narrow-mouthed frogs, is a genus of frogs in the family Microhylidae. It consists of 42 species of diminutive frogs. Members of this genus are widespread from Ryukyu Is. in Japan, and throughout ...

'' Tschudi, 1838 ** genus '' Micryletta'' Dubois, 1987 ** genus '' Mysticellus'' Sonali & Biju, 2019 **genus '' Nanohyla'' ** genus '' Phrynella'' Boulenger, 1887 ** genus '' Uperodon'' Duméril & Bibron, 1841 * subfamily Otophryninae Wassersug & Pyburn, 1987 ** genus '' Otophryne'' Boulenger, 1900 ** genus '' Synapturanus'' Carvalho, 1954 * subfamily Phrynomerinae Noble, 1931 ** genus '' Phrynomantis'' Peters, 1867 * subfamily Scaphiophryninae Laurent, 1946 ** genus '' Paradoxophyla'' Blommers-Schlösser & Blanc, 1991 ** genus '' Scaphiophryne'' Boulenger, 1882

Range

Frogs from the Microhylidae occur throughout the tropical and warm temperate regions of North America, South America, Africa, eastern India, Sri Lanka, Southeast Asia, New Guinea, and Australia. Although most are found in tropical or subtropical regions, a few species can be found in arid or nontropical areas. They are the majority of frog species in New Guinea and Madagascar. The ranges of each subfamily are:De Sá, R. O., Streicher, J. W., Sekonyela, R., Forlani, M. C., Loader, S. P., Greenbaum, E., … Haddad, C. F. B. (2012). Molecular phylogeny of microhylid frogs (Anura: Microhylidae) with emphasis on relationships among New World genera. BMC Evolutionary Biology, 12, 241. http://doi.org/10.1186/1471-2148-12-241 * Hoplophryninae:

Africa Africa is the world's second-largest and second-most populous continent, after Asia in both cases. At about 30.3 million km2 (11.7 million square miles) including adjacent islands, it covers 6% of Earth's total surface area ...

* Scaphiophryninae: Madagascar * Dyscophinae: Madagascar * Microhylinae: Southeast Asia, East Asia, South Asia *

: Australia, New Guinea * Phrynomerinae:

* Kalophryninae: Southeast Asia * Otophyninae: South America *

: Madagascar * Gastrophryninae: New World *

: South Asia * Chaperininae: Southeast Asia * Adelastinae: South America

References

External links

* {{Taxonbar, from=Q56057 Extant Miocene first appearances Taxa named by Albert Günther Amphibian families