Dissecting the major American snake radiation: A molecular phylogeny of the Dipsadidae Bonaparte (Serpentes, Caenophidia)

Abstract

The Dipsadidae contains more than 700 extant species belonging to 92 genera and is the largest family of American snakes. In this work, we built a data set including two mitochondrial genes (12S and 16S rRNA) for 125 dipsadid taxa belonging to 59 genera, in order to gain further insights on the phylogenetic relationships of this large group at the subfamilial and generic levels. Among dipsadines, the monotypic genus Nothopsis is the sister-group to Leptodeira. Among xenodontines, the monophyly of seven previously recognized tribes (Alsophiini, Elapomorphini, Hydropsini, Philodryadini, Pseudoboini, Tachymenini and Xenodontini) is confirmed. Among Xenodontini, the genus Liophis is paraphyletic with respect to Erythrolamprus and Umbrivaga and workers should be aware of the inadequacy of the current taxonomy. Finally, the following genera could not confidently be allocated to the above tribes: Caaeteboia, Echinantera and Taeniophallus, Tropidodryas, Manolepis and Pseudalsophis, Xenopholis, Psomophis, Hydrodynastes, Conophis and Crisantophis.

Molecular phylogeny of advanced snakes (Serpentes, Caenophidia) with an emphasis on South American Xenodontines: a revised classification and descriptions of new taxa

“…The Xenodermatinae (Clade 2; represented by Xenodermus and Stoliczkia) is a basally diverging clade among caenophidians in our study, as well as Kelly et al (2003), Vidal & Hedges (2002a,b), and Vidal et al (2008). Some other molecular studies (e.g., Lawson et al, 2005;Kelly et al, 2009) found a radically different phylogenetic position for xenodermatines based on molecular sequences for Oxyrhabdium, which is typically included within this group.…”

“…Subsequently, Pinou et al (2004) applied the resurrected name "Elapoidea" to a clade comprising Atractaspis + Elapidae. "Elapoidea" has subsequently been used for "Clade A" of Lawson et al (2005) in several molecular phylogenetic studies (Vidal et al, 2007(Vidal et al, , 2008; Kelly et al, 2009; see also our results below). Clade B of Lawson et al (2005) was referred to as "Colubroidea" by Pinou et al (2004) and subsequent authors.…”

“…Corrections and modifications to Zaher's (1999) generic arrangement followed in several molecular studies, which concentrated on the "boodontine" and psammophiine lineages, and in the placement of the North American xenodontines (Pinou et al, 2004;Lawson et al, 2005;Vidal et al, 2007Vidal et al, , 2008. Most importantly, the paraphyletic family Colubridae was redefined as a much more restrictive group, and most of the subfamilies recognized by Zaher (1999) were rearranged among various families and superfamilies (Pinou et al, 2004;Lawson et al, 2005;Vidal et al 2007Vidal et al , 2008. Lawson et al (2005) revised the allocation of many genera based on a molecular phylogeny of 100 caenophidians representing all subfamilies recognized by Zaher (1999).…”

“…They were the first to recognize the basal rooting of the Xenodermatinae on the basis of molecular data, although various authors (e.g., Boulenger, 1894) had long recognized their relative basal position within caenophidians. Corrections and modifications to Zaher's (1999) generic arrangement followed in several molecular studies, which concentrated on the "boodontine" and psammophiine lineages, and in the placement of the North American xenodontines (Pinou et al, 2004;Lawson et al, 2005;Vidal et al, 2007Vidal et al, , 2008. Most importantly, the paraphyletic family Colubridae was redefined as a much more restrictive group, and most of the subfamilies recognized by Zaher (1999) were rearranged among various families and superfamilies (Pinou et al, 2004;Lawson et al, 2005;Vidal et al 2007Vidal et al , 2008.…”

“…Clade B of Lawson et al (2005) was referred to as "Colubroidea" by Pinou et al (2004) and subsequent authors. Vidal et al (2007Vidal et al ( , 2008) studied broad patterns of phylogenetic relationships among caenophidians based on an analysis of sequences from approximately 25-30 taxa, primarily from Africa, and revised some of the taxonomy of snakes based on their analyses. However, we feel that some of their formally recognized taxa are only weakly supported by their molecular data, or receive conflicting phylogenetic signals in different data sets.…”