Molecular phylogeny of the tribe Philodryadini Cope, 1886 (Dipsadidae: Xenodontinae): Rediscovering the diversity of the South American Racers

Juan Camilo Arredondo,Hussam El Dine Zaher,Miguel Trefaut Urbano Rodrigues,Sandro Luís Bonatto,Felipe Gobbi Grazziotin,Gustavo Jose Scrocchi Manfrini

doi:10.11606/1807-0205/2020.60.53

Abstract

South American racers of the tribe Philodryadini are a widespread and diverse group of Neotropical snakes with a complex taxonomic and systematic history. Recent studies failed to present a robust phylogenetic hypothesis for the tribe, mainly due to incomplete taxon sampling. Here we provide the most extensive molecular phylogenetic analysis of Philodryadini available so far, including 20 species (83% of the known diversity) from which six were not sampled previously. Our results reveal that Philodryadini is not monophyletic, but instead includes a central Andean clade formed by Philodryas simonsii, P. tachymenoides, and P. amaru, and a southern and cis-Andean clade including all remaining philodryadines. This discovery requires resurrection of two genera as well as erection of a new tribe of Xenodontinae for the central Andean clade. Within the southern and cis-Andean radiation, our analyses resolve a basal dichotomy separating two main lineages: Clade A, containing the Common Green Racers P. laticeps and P. viridissima and the South American Vine snakes P. georgeboulengeri and P. argentea; and Clade B, including the remaining species of Philodryas sensu stricto. We resurrect the genera Chlorosoma and Xenoxybelis to better represent the monophyly of lineages within the southern and cis-Andean clade.

Highlights

The South American racers of the tribe Philodryadini Cope 1886 are a diverse and widespread group of snakes with a wide variety of morphologies and ecological roles, ranging from large, semiarboreal, and generalist species to small, secretive, and diet specialist species (Greene & Jaksic, 1992; Hartmann & Marques, 2005; Marques et al, 2006)
Our results reveal that Philodryadini is not monophyletic, but instead includes a central Andean clade formed by Philodryas simonsii, P. tachymenoides, and P. amaru, and a southern and cis-Andean clade including all remaining philodryadines
The maximum likelihood (ML) and Bayesian Inference phylogenetic analysis (BI) tree topologies showed very similar higher-level relationships, with Colubridae, Natricidae, Sibynophiidae, and Dipsadidae being all recovered as monophyletic lineages with robust to unambiguous support values

Summary

Introduction

The South American racers of the tribe Philodryadini Cope 1886 are a diverse and widespread group of snakes with a wide variety of morphologies and ecological roles, ranging from large, semiarboreal, and generalist species to small, secretive, and diet specialist species (Greene & Jaksic, 1992; Hartmann & Marques, 2005; Marques et al, 2006). Most of this diversity occurs along the cis-Andean portion of South America (Table 1).

Methods

Results

Conclusion