Early evolution of discoglossid frogs: new evidence from the Mesozoic of China

摘要

The Anura hold an important position in the history of the vertebrates as a major lissamphibian group. Although Cenozoic anuran record is fairly well documented from North America and Eurasia, Mesozoic fossils of the group are too inadequate to be illuminative of the early evolution of the group (Estes and Reig 1973; Sanchiz 1998). Among extant anurans, the family Discoglossidae is a primitive group which, together with Leiopelmatidae, was regarded as the most basal clade of living anurans (Estes and Reig 1973; Duellman and Trueb 1986; Sanchiz 1998). However, the taxon-omic composition and the monophyly of the Discoglossidae are quite controversial (Cannatella 1985; Clarke 1988; Ford and Cannatella 1993a; Baez and Basso 1996), and no phylogenetic analyses have included both extant and the fossil taxa that have been attributed to the family.