Pipoidea are a

clade A clade (), also known as a monophyletic group or natural group, is a group of organisms that are monophyletic – that is, composed of a common ancestor and all its lineal descendants – on a phylogenetic tree. Rather than the English term, ...

of frogs that have variously been defined as a suborder (original definition), superfamily, or an unranked

node-based taxon Phylogenetic nomenclature is a method of nomenclature for taxa in biology that uses phylogenetic definitions for taxon names as explained below. This contrasts with the traditional approach, in which taxon names are defined by a '' type'', which ...

. There is no single, authoritative higher-level classification of frogs, and Vitt and Caldwell (2014) use name Xenoanura for a similar clade, skipping Pipoidea altogether, as did Frost ''et al.'' (2006). In 1993 Pipoidea was defined by Ford and Cannatella as the node-based taxon that contains the most recent common ancestor of living Pipidae and

Rhinophrynidae The Rhinophrynidae are a family of frogs containing one extant genus, the monotypic '' Rhinophrynus'', and a number of fossil genera. The family is sometimes known as the Mexican burrowing toads or simply burrowing toads. ''Rhinophrynus'' occur ...

as well as all its descendants: The

synapomorphies In phylogenetics, an apomorphy (or derived trait) is a novel character or character state that has evolved from its ancestral form (or plesiomorphy). A synapomorphy is an apomorphy shared by two or more taxa and is therefore hypothesized to have ...

that define Pipoidea are the absence of mentomeckelian bones, absence of lateral alae of the parasphenoid, fusion of the frontoparietals into an azygous element, greatly enlarged otic capsules, and a

tadpole A tadpole is the larval stage in the biological life cycle of an amphibian. Most tadpoles are fully aquatic, though some species of amphibians have tadpoles that are terrestrial. Tadpoles have some fish-like features that may not be found i ...

with paired

spiracle Spiracle or spiraculum may refer to: * Spiracle (arthropods), opening in the exoskeletons of some arthropods * Spiracle (vertebrates), openings on the surface of some vertebrates * Spiraculum, a genus of land snails in family Cyclophoridae Cycl ...

s and which lacks beaks and denticles. Later genetic work has supported Pipoidea as a

monophyletic In cladistics for a group of organisms, monophyly is the condition of being a clade—that is, a group of taxa composed only of a common ancestor (or more precisely an ancestral population) and all of its lineal descendants. Monophyletic gro ...

group. The oldest record of the group is ''

Rhadinosteus ''Rhadinosteus parvus'' (meaning "long slender bone") is an extinct species of prehistoric frogs that lived during the Late Jurassic.Foster, J. (2007). "''Rhadinosteus parvus''." ''Jurassic West: The Dinosaurs of the Morrison Formation and Their ...

'' from the Late Jurassic of North America, which is more closely related to Rhinophrynidae than to Pipidae. The oldest records of the Pipimorpha, which contains all pipoids more closely related to Pipidae than to Rhinophrynidae, are during the Early Cretaceous.

References

{{Taxonbar, from=Q16935324 Taxa named by Raymond Laurent