Molecular phylogenetic evidence for paraphyly of the genus Sooglossus, with the description of a new genus of Seychellean frogs

Abstract

The Seychelles harbour an endemic frog family, the Sooglossidae, currently containing two genera: Sooglossus , with three species, and Nesomantis , with one species. These unique frogs are generally considered to be basal neobatra- chians, although their relationships to other neobatrachian taxa, except the Nasikabatrachidae, remain unresolved. Our molecular phylogeny based on a dataset consisting of fragments of the nuclear rag-1 and rag-2 genes, as well as mitochondrial 16S rRNA in representatives of the major neobatrachian lineages, confirmed the previously postu- lated Sooglossidae + Nasikabatrachidae clade and the placement of the South American Caudiverbera with the Aus- tralian Myobatrachidae, but did not further resolve the position of sooglossids. Our results do, however, unambiguously show sooglossids to be monophyletic but the genus Sooglossus to be paraphyletic, with the type spe- cies Sooglossus sechellensis being more closely related to Nesomantis thomasseti than to Sooglossus gardineri and Sooglossus pipilodryas , in agreement with morphological, karyological, and bioacoustic data. As a taxonomic con- sequence, we propose to consider the genus name Nesomantis as junior synonym of Sooglossus , and to transfer the species thomasseti to Sooglossus . For the clade composed of the species gardineri and pipilodryas , here, we propose the new generic name Leptosooglossus . A significant genetic differentiation of 3% was found between specimens of Sooglossus thomasseti from the Mahe and Silhouette Islands, highlighting the need for further studies on their pos- sible taxonomic distinctness. © 2007 The Linnean Society of London, Biological Journal of the Linnean Society , 2007, 91 , 347-359. ADDITIONAL KEYWORDS: Amphibia - Anura - biogeography - Leptosooglossus - molecular phylogeny - Nesomantis - new genus - Sooglossidae - Sooglossus .