A new species of &lt;i&gt;Dipsas&lt;/i&gt; (Squamata: Colubridae) from Guyana

Ross D Macculloch,Amy Lathrop

doi:10.15517/rbt.v52i1.14916

Abstract

A new species of Dipsas is described from the Pakaraima Mountains of Guyana. The new species is characterised by 15 dorsal scale rows with the middorsal row slightly enlarged. four pairs of chinshields with the first pair elongate, elongate loreal entering orbit, one preocular, six upper labials, and head narrow anteriorly, increasing in width posteriorly. It could not be determined to which of Peters' (1960) species groups the new species belongs. The new species is known only from 1490 m elevation on Mount Ayanganna. a tepui in the Guiana Shield, where it was found in high-tepui low-canopy habitat, in bromeliads or branches. This is the first record of Dipsas as a member of the Guiana Shield high-tepui herpetofauna.

Highlights

Dipsadine snakes constitute a morphologically unique group of the Neotropical Colubridae
The most recent thorough review of the genus Dipsas Laurenti 1768 was by Peters (1960), who recognized 32 species, and divided them into seven species groups based primarily on colour pattern
A new species of Dipsas from Bolivia was described by Reynolds and Foster (1992)

Summary

Introduction

Dipsadine snakes constitute a morphologically unique group of the Neotropical Colubridae. The members of this group exhibit a number of characters specialised for an arboreal malacophagous life such as lateral compression of the body, reduction or loss of the mental groove and inward angling of the maxillary teeth. The most recent thorough review of the genus Dipsas Laurenti 1768 was by Peters (1960), who recognized 32 species, and divided them into seven species groups based primarily on colour pattern. Five species (D. catesbyi, D. copei, D. indica, D. pavonina and D. variegata), as well as the dipsadine Sibon nebulata, occur in the Guiana region of northeastern South America (Peters 1960, Roze 1966, Peters and Orejas-Miranda 1970, Chippaux 1986, Starace 1998, Kornacker 1999). Recent collections from Mount Ayanganna, in the Pakaraima mountains of western Guyana, included specimens of a new species of Dipsas

Methods

Findings

Conclusion