species, male or female toads may possess a Bidder's organ, a trait unique to all bufonids except genera Melanophryniscus and Truebella. Under the right conditions, the organ becomes an active ovary. The loss of teeth has arisen in frogs independently over 20 times. Notably, all members of Bufonidae are toothless. Another Anuran family with a comparable degree of edentulism is the family Microhylidae. Reproduction Internal fertilization occurs in four bufonid genera. Mertensophryne (some species) Nectophrynoides (presumably all species) Altiphrynoides malcolmi (one out of two species in the genus Altiphrynoides) Nimbaphrynoides occidentalis (the sole species in the monotypic genus Nimbaphrynoides) Ascaphus (all species) and Eleutherodactylus (two species, E. coqui and E. jasperi) are the only other frog genera that have internal fertilization. Limnonectes larvaepartus also has internal fertilization. Taxonomy and genera The family Bufonidae contains over 570 species among 52 genera. References Stebbins, Robert. Western Reptiles & Amphibians (3rd ed.). Houghton Mifflin Co., 2003. Halliday, Tim R., and Kraig Adler (editors). The New Encyclopedia of Reptiles & Amphibians. Facts on File, New York, 2002. External links Tolweb.org: Bufonidae Bufonidae.com Amphibian and Reptiles of Peninsular Malaysia - Family Bufonidae FED.us Bufonidae recordings from the British Library Sound Archive Extant Thanetian first appearances Amphibian families Taxa named by John Edward Gray