Microhylidae

The Microhylidae, commonly known as narrow-mouthed frogs, are a geographically widespread family of frogs. The 683 species are in 57 genera and 11 subfamilies.

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 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 termites and ants, 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 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 palatines 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 GÃÂ¼nther, 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 Boettger, 1892
genus Gastrophrynoides Noble, 1926
genus Hylophorbus Macleay, 1878
genus Mantophryne Boulenger, 1897
genus Oninia GÃÂ¼nther, Stelbrink & von Rintelen, 2010
genus Oreophryne Boettger, 1895
genus Paedophryne Kraus, 2010
genus Siamophryne Suwannapoom, Sumontha, Tunprasert, Ruangsuwan, Pawangkhanant, Korost, and Poyarkov, 2018
genus Sphenophryne Peters & Doria, 1878
genus Vietnamophryne Poyarkov, Suwannapoom, Pawangkhanant, Aksornneam, Duong, Korost and Che, 2018
genus Xenorhina Peters, 1863
subfamily Chaperininae Peloso, Frost, Richards, Rodrigues, Donnellan, Matsui, Raxworthy, Biju, Lemmon, Lemmon, & Wheeler, 2015
genus Chaperina Mocquard, 1892
subfamily Cophylinae Cope, 1889
genus Anilany Scherz, Vences, Rakotoarison, Andreone, KÃÂ¶hler, Glaw, and Crottini, 2016
genus Anodonthyla MÃÂ¼ller, 1892
genus Cophyla Boettger, 1880
genus Mini Scherz, Hutter, Rakotoarison, Riemann, RÃÂ¶del, 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 Ctenophryne Mocquard, 1904
genus Dasypops Miranda-Ribeiro, 1924
genus Elachistocleis Parker, 1927
genus Gastrophryne 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 Noble, 1931
genus Melanobatrachus Beddome, 1878
subfamily Microhylinae GÃÂ¼nther, 1858
genus Glyphoglossus Gunther, 1869 "1868"
genus Kaloula Gray, 1831
genus Metaphrynella Parker, 1934
genus Microhyla Tschudi, 1838
genus Micryletta Dubois, 1987
genus Mysticellus Sonali & Biju, 2019
genus Nanohyla
genus Phrynella Boulenger, 1887
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-SchlÃÂ¶sser & 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: