Phylogeny, diversity and biogeography of Neotropical sipo snakes (Serpentes: Colubrinae: Chironius)

Molecular phylogeny of Neotropical Parrot Snakes (Serpentes: Colubrinae: Leptophis) supports underestimated species richness

Tetrapod taxa with broad geographic distributions across the Neotropics are often composed of multiple evolutionary lineages. In this paper, we present the most complete phylogeny of Leptophis to date and assess morphology-based species limits within the broadly distributed green parrot snake Leptophis ahaetulla sensu lato, which occurs from Mexico to Argentina. Although L. ahaetulla sensu stricto, L. nigromarginatus and L. occidentalis were recovered as paraphyletic, tree topology tests failed to reject their monophyly. Monophyly of L. bocourti, L. coeruleodorsus, L. cupreus, L. depressirostris, L. marginatus, L. riveti and L. sp. nov. was strongly supported. Our phylogenetic trees support recognition of multiple species within Leptophis ahaetulla sensu lato and suggest that color evolution and the uplift of the Andes played an important role in the diversification of parrot snakes.

Hidden diversity in two widespread snake species (Serpentes: Xenodontini: Erythrolamprus) from South America

The spatial distribution of genetic diversity of widely distributed Neotropical tetrapods has been an active research field during the last decade, although it has focused on lowland (mostly Amazonian) taxa. In this paper we use phylogenetic analyses to explore the diversity within two widely distributed snake species, Erythrolamprus epinephelus and E. reginae. Specifically, we focus on Andean populations of the former and lowland samples of the latter. Our results show that Erythrolamprus epinephelus is paraphyletic and support recognition of the subspecies albiventris, fraseri and lamonae as distinct species. Regarding E. reginae, our results are in conflict with recent taxonomic proposals in that (1) E. reginae is paraphyletic, and (2) E. zweifeli from Trinidad and E. reginae from Amazonian Ecuador are not reciprocally monophyletic. Finally, we recommend caution when proposing taxonomic changes based on incomplete geographic and/or character sampling of widespread Neotropical taxa.

The Western Amazonian Richness Gradient for Squamate Reptiles: Are There Really Fewer Snakes and Lizards in Southwestern Amazonian Lowlands?

The lowland rainforests of the Amazon basin harbor some of the most species-rich reptile communities on Earth. However, there is considerable heterogeneity among climatically-similar sites across the Amazon basin, and faunal surveys for southwestern Amazonia in particular have revealed lower species diversity relative to sites in the northwestern and central Amazon. Here, we report a herpetofaunal inventory for Los Amigos Biological Station (LABS), a lowland site located in the Madre de Dios watershed of southern Peru. By combining active search and passive trapping methods with prior records for the site, we provide a comprehensive species list for squamate reptiles from LABS. We also estimate an “expected” list for LABS by tabulating additional taxa known from the regional species pool that we consider to have a high probability of detection with further sampling. The LABS total of 60 snake and 26 lizard taxa is perhaps the highest for any single site in the southern Amazon. Our estimate of the regional species pool for LABS suggests that the southwestern Amazonian lowlands harbor at least 25% fewer species of snakes relative to the western equatorial Amazon, a diversity reduction that is consistent with patterns observed in several other taxonomic groups. We discuss potential causes of this western Amazonian richness gradient and comment on the relationship between spatial diversity patterns in squamates and other taxa in the Amazon basin.