Archaeobatrachia

Archaeobatrachia is a historical suborder of frogs within the order Anura, used in traditional taxonomy to designate the most primitive or early-diverging lineages. It stands in contrast to Neobatrachia, which contains the vast majority of living frogs and toads. In many modern phylogenetic analyses Archaeobatrachia is not recovered as a single natural group, and the term is most often encountered in historical or descriptive contexts rather than as a formal clade.

Traditionally, several families were associated with Archaeobatrachia, including Ascaphidae (tailed frogs) of North America; Bombinatoridae (fire-bellied toads); Pelobatidae (spadefoot toads); Discoglossidae (discoglossins); and Alytidae (midwife toads and relatives). The exact composition has varied among authors, with Discoglossidae sometimes treated separately or merged with Alytidae, and Pelobatidae placed in broader early-diverging lineages. This variability reflects the non-monophyletic and transitional nature historically attributed to the group.

In anatomical and life-history terms, archaeobatrachian frogs were viewed as retaining more plesiomorphic features than most modern frogs. The fossil record for these lineages extends to the Mesozoic, illustrating early diversification within Anura. Today, the term Archaeobatrachia is primarily of historical interest; many taxa once placed here are now assigned to other lineages within Neobatrachia or related groups in contemporary classifications.