A molecular perspective on the evolutionary affinities of an enigmatic neotropical frog, Allophryne ruthveni

The phylogenetic relationships of neobatrachian frogs remain poorly resolved below the subordinal level. The neotropical frog Allophryne ruthveni (Gaige) illustrates the difficulty in evaluating phylogenetic relationships within the Neobatrachia. Since its discovery in 1926, it has been variously placed within five different anuran families: Bufonidae, Leptodactylidae, Centrolenidae, Hylidae and in its own monotypic family, Allophrynidae. Here we examine the evolutionary relationships of Allophryne ruthveni using DNA sequence data from two mitochondrial genes (16S and 12S rRNA). Our analyses suggest that Allophryne ruthveni is most closely allied to the glass frogs (Centrolenidae). Both 12S and combined data partitions support an Allophryne ruthveni–Cochranella midas– Centrolene geckoideum clade, with Allophryne ruthveni basally positioned. Considered alone, analyses of the 16S partition supports the placement of Allophryne ruthveni with the centrolenids only with neighbour-joining analyses. The placement of Allophryne ruthveni with the centrolenids supports Noble's (1931 ) hypothesis that Allophryne is an edentate centrolenid. More definitive statements of the evolutionary affinities of Allophryne ruthveni in particular, and the Neobatrachia in general, await greater sampling of taxa and both molecular and phenotypic (e.g. morphological and karyotypic) characters. © 2002 The Linnean Society of London. Zoological Journal of the Linnean Society , 2002, 134 , 335–346.