Brachycephaloidea (or Terrarana) is a large

monophyletic In biological cladistics for the classification of organisms, monophyly is the condition of a taxonomic grouping being a clade – that is, a grouping of organisms which meets these criteria: # the grouping contains its own most recent co ...

unranked

clade In biology, a clade (), also known as a Monophyly, monophyletic group or natural group, is a group of organisms that is composed of a common ancestor and all of its descendants. Clades are the fundamental unit of cladistics, a modern approach t ...

of direct-developing frogs including more than 1,100 species, comprising about 15% of named frog species. Brachycephaloids inhabit the

New World The term "New World" is used to describe the majority of lands of Earth's Western Hemisphere, particularly the Americas, and sometimes Oceania."America." ''The Oxford Companion to the English Language'' (). McArthur, Tom, ed., 1992. New York: ...

tropics The tropics are the regions of Earth surrounding the equator, where the sun may shine directly overhead. This contrasts with the temperate or polar regions of Earth, where the Sun can never be directly overhead. This is because of Earth's ax ...

subtropics The subtropical zones or subtropics are geographical and climate zones immediately to the north and south of the tropics. Geographically part of the temperate zones of both hemispheres, they cover the middle latitudes from to approximately ...

, and

Andean The Andes ( ), Andes Mountains or Andean Mountain Range (; ) are the longest continental mountain range in the world, forming a continuous highland along the western edge of South America. The range is long and wide (widest between 18°S ...

regions. The group has undergone extensive changes in its

taxonomy image:Hierarchical clustering diagram.png, 280px, Generalized scheme of taxonomy Taxonomy is a practice and science concerned with classification or categorization. Typically, there are two parts to it: the development of an underlying scheme o ...

thanks to multiple molecular

phylogenetic In biology, phylogenetics () is the study of the evolutionary history of life using observable characteristics of organisms (or genes), which is known as phylogenetic inference. It infers the relationship among organisms based on empirical dat ...

analyses in recent years. Until 2008, these species were placed in a single, large family (Brachycephalidae). The diverse Brachycephaloidea contains several notable taxa. It includes the smallest known vertebrates, in the genus '' Brachycephalus'' (family

Brachycephalidae The Brachycephalidae () are a family of frogs confined to eastern and southern Brazil and northern Argentina. The family is composed of two externally quite different genera: the tiny, often (but not always) colourful and plump saddleback toads ...

): '' B. pulex'' and '' B. dacnis''. It also holds the most specious vertebrate genus, ''

Pristimantis ''Pristimantis'' is a very specious genus of frogs distributed in the southern Caribbean islands (Lesser Antilles) and in Central and South America from Honduras to northern Argentina and southern Brazil. With 617 described species (as of Februa ...

'' (family

Strabomantidae The Strabomantidae, sometimes called cloud forest landfrogs, are a family of frogs native to South America. These frogs lack a free-living larval stage and hatch directly into miniature "froglets". This family includes '' Pristimantis'', the mo ...

References

Tetrapod unranked clades {{Brachycephaloidea-stub