Species delimitation, patterns of diversification and historical biogeography of the Neotropical frog genus Adenomera (Anura, Leptodactylidae)

Abstract

Aim For many taxa, inaccuracy of species boundaries and distributions hampers inferences about diversity and evolution. This is particularly true in the Neotropics where prevalence of cryptic species has often been demonstrated. The frog genus Adenomera is suspected to harbour many more species than the 16 currently recognized. These small terrestrial species occur in Amazonia, Atlantic Forest (AF), and in the open formations of the Dry Diagonal (DD: Chaco, Cerrado and Caatinga). This widespread and taxonomically complex taxon provides a good opportunity to (1) test species boundaries, and (2) investigate historical connectivity between Amazonia and the AF and associated patterns of diversification.Location Tropical South America east of the Andes.Methods We used molecular data (four loci) to estimate phylogenetic relationships among 320 Adenomera samples. These results were integrated with other lines of evidence to propose a conservative species delineation. We subsequently used an extended dataset (seven loci) and investigated ancestral area distributions, dispersal-vicariance events, and the temporal pattern of diversification within Adenomera. ResultsOur conservative delineation identified 31 Confirmed Candidate Species (four remaining unconfirmed) representing a 94% increase in species richness. The biogeographical analysis suggested an Amazonian origin of Adenomera with as many as three dispersals to the DD and one to the AF during the Miocene. These dispersals were associated with habitat shifts from forest towards open habitats. Main conclusionsThe DD played a major role in the history of Adenomera in limiting dispersal and favouring diversification of open-habitat lineages. Moreover, a forest bridge during the Miocene Climatic Optimum may have permitted dispersal from Amazonia towards the AF and subsequent diversification. Uncovering species boundaries and distributions might drastically change inferences based on currently perceived distribution patterns.

Molecular phylogeny, species limits, and biogeography of the Brazilian endemic lizard genus Enyalius (Squamata: Leiosauridae): An example of the historical relationship between Atlantic Forests and Amazonia

“…This is in agreement with dates estimated for distinct groups of vertebrates such as reptiles (Grazziotin et al, 2006;Siedchlag et al, 2010), frogs (Thomé et al, 2010;Amaro et al, 2012;Fouquet et al, 2014), birds (Patel et al, 2011), and mammals (Costa, 2003).…”

“…For suboscine passeriforms, Batalha-Filho et al (2013) identified two distinct spatiotemporal pathways connecting the Atlantic and the Amazonian forests: (1) old connections (middle to late Miocene) through the current southern Cerrado and Mato Grosso, and the transition towards the Chaco and palm savannas of Bolivia and Paraguay; and (2) young connections (Pliocene to Pleistocene) that possibly occurred through the Cerrado and Caatinga in northeastern Brazil. Leptodactylid frogs of the genus Adenomera, originally from Amazonia, entered the AF, Dry Forest and Cerrado by the middle Miocene (Fouquet et al, 2014). This was also the period in which the Amazonian representatives of centrolenid frogs of the genus Vitreorana entered the AF (Castroviejo-Fisher et al, 2014), and the approximate time of divergence between Amazonian and AF gymnophthalmid lizards of the genus Leposoma (Pellegrino et al, 2011).…”

Out of the deep: Cryptic speciation in a Neotropical gecko (Squamata, Phyllodactylidae) revealed by species delimitation methods

“…The levels of biodiversity in this region remain relatively unknown (Fouquet et al, 2007(Fouquet et al, , 2014Scheffers et al, 2012) and a large amount of species is still waiting to be discovered (Costello et al, 2013;Mora et al, 2011;Wheeler et al, 2012). The Brazilian Cerrado is the largest Neotropical savanna (Eiten, 1972;Oliveira and Marquis, 2002) and one of the world's formally recognized biodiversity hotspots (Myers et al, 2000).…”

The herpetofauna of Parque Nacional da Serra das Confusões, state of Piauí, Brazil, with a regional species list from an ecotonal area of Cerrado and Caatinga

“…Another three are candidates to new species. Adenomera sp., was detected as a possible new species in a recent molecular study (Fouquet et al 2014). This species also occurs at EEUU, being probably distributed along the northern Cerrado and ecotonal areas between this domain and the neighbors.…”