Leptolalax

{{Short description|Genus of amphibians}}

{{automatic taxobox

| image = Leptolalax melanoleucus from Thailand.jpg

| image_caption = Leptolalax melanoleucus

| taxon = Leptolalax

| authority = Dubois, 1980

| type_species = Leptolalax bourreti

| type_species_authority = Dubois, 1983

| subdivision_ranks = Species

| subdivision =

50, see text

}}

Leptolalax is a genus of frogs (order Anura) in the family Megophryidae. They are sometimes known as Asian toads, metacarpal-tubercled toads, or slender litter frogs, although many species-specific common names do not follow these conventions, and many species do not have common names. They are widely distributed in southeastern and eastern Asia, from southern China and northeastern India to the Malay Peninsula and Borneo.{{cite web |url=http://research.amnh.org/vz/herpetology/amphibia/?action=names&genus=Leptolalax |title= Leptolalax Dubois, 1980|author=Frost, Darrel R. |year=2014 |work=Amphibian Species of the World: an Online Reference. Version 6.0 |publisher=American Museum of Natural History |access-date=18 January 2014}} Leptolalax are typically small and have a cryptic colour pattern and no obvious morphological characters useful in systematic studies. Consequently, both molecular genetic analyses and analysis of advertisement calls by male frogs have been important in identifying new species.{{cite journal | last1 = Matsui | first1 = M. | year = 1997 | title = Call characteristics of Malaysian Leptolalax with a description of two new species (Anura: Pelobatidae) | journal = Copeia | volume = 1997 | issue = 1 | pages = 158–165 | jstor = 1447851 | doi=10.2307/1447851}}{{Cite journal | volume = 3147| pages = 1–83| last = Ohler| first = A.|author2=K. C. Wollenberg |author3=P. Grosjean |author4=R. Hendrix |author5=M. Vences |author6=T. Ziegler |author7=A. Dubois | title = Sorting out Lalos: description of new species and additional taxonomic data on megophryid frogs from northern Indochina (genus Leptolalax, Megophryidae, Anura)| journal = Zootaxa| year = 2011| doi = 10.11646/zootaxa.3147.1.1| url = http://www.mapress.com/zootaxa/list/2011/3147.html}}

File:Leptolalax liui.jpg]]

Two subgenera are recognized: Leptolalax and Lalos (the latter was first named as Lalax, but the name was already occupied). Lalos has a more northern distribution and only includes species from the continental Asia, whereas Leptolalax includes all the species from Borneo (Leptolalax arayai, Leptolalax dringi, Leptolalax fritinniens, Leptolalax gracilis, Leptolalax hamidi, Leptolalax maurus, Leptolalax sabahmontanus, Leptolalax marmoratus and Leptolalax pictusA Field Guide to the Frogs of Borneo, Third Edition) as well as few continental species (Leptolalax croceus, Leptolalax melicus) and Leptolalax kajangensis from Tioman Island, at least provisionally.

Most Leptolalax species have been reported from very small areas and only a few species have large areas of occurrence. Whether this distinction is real or the widespread species represent cryptic species complexes remains to be confirmed.