The Brachycephalidae () are a

family Family (from ) is a Social group, group of people related either by consanguinity (by recognized birth) or Affinity (law), affinity (by marriage or other relationship). It forms the basis for social order. Ideally, families offer predictabili ...

frog A frog is any member of a diverse and largely semiaquatic group of short-bodied, tailless amphibian vertebrates composing the order (biology), order Anura (coming from the Ancient Greek , literally 'without tail'). Frog species with rough ski ...

s confined to eastern and southern

Brazil Brazil, officially the Federative Republic of Brazil, is the largest country in South America. It is the world's List of countries and dependencies by area, fifth-largest country by area and the List of countries and dependencies by population ...

and northern

Argentina Argentina, officially the Argentine Republic, is a country in the southern half of South America. It covers an area of , making it the List of South American countries by area, second-largest country in South America after Brazil, the fourt ...

. The family is composed of two externally quite different

genera Genus (; : genera ) is a taxonomic rank above species and below family as used in the biological classification of living and fossil organisms as well as viruses. In binomial nomenclature, the genus name forms the first part of the binomial s ...

: the tiny, often (but not always) colourful and plump saddleback toads ('' Brachycephalus'') from Brazil, and the larger, slimmer and more drab genus '' Ischnocnema'' from both Brazil and Argentina. The family is mainly defined by molecular characteristics, and are linked by few anatomical features. It was erected from two genera of the previously large family Eleutherodactylidae, which is now split into four families. The Brachycephalidae all have direct development and hatch like miniature adults rather than as

tadpole A tadpole or polliwog (also spelled pollywog) is the Larva, larval stage in the biological life cycle of an amphibian. Most tadpoles are fully Aquatic animal, aquatic, though some species of amphibians have tadpoles that are terrestrial animal, ...

s like most frogs. The members of the genus ''Brachycephalus'' are all very diminutive animals, with many species under in snout–to– vent length.

References

Amphibian families Taxa named by Albert Günther {{Brachycephaloidea-stub