On Gymnodactylus amarali Barbour, 1925, with the description of a new species (Sauria, Gekkonidae)

Paulo Emilio Vanzolini

doi:10.1590/s0001-37652005000400003

Abstract

Gymnodactylus amarali Barbour, 1925, was previously considered to be a subspecies of G. geckoides, with a wide distribution in the Brasilian cerrados. Examination of a specimen from Alto Parnaíba, Maranhão, near the type locality (Engenheiro Dodt, Piauí), indicates that it is a proper species, apparently limited to the upper Parnaíba basin. The form previously identified as G. geckoides amarali is described as a new species, G. carvalhoi, type locality Ipueiras, State of Tocantins, thus diagnosed: color pattern plain or, more often, with moderately contrasted ocelli; dorsal tubercles in 13-16 poorly organized longitudinal rows (mode 14, 72%); 31-49 tubercles in a paramedian row; 17-22 transverse rows of ventral scales; 13-18 infradigital lamellae on toe IV; tail longest in the genus. The new species is statistically compared to parapatric G. geckoides, widespread in the caatingas. Although only one meristic character (number of tubercle rows) is by itself diagnostic, the species are easily told apart. It is thought on provisional evidence that they are better considered for the time being as full species, not subspecies. A brief consideration is made of the speciation model that seems suitable, to wit, parapatric.

Highlights

In a review of the genus Gymnodactylus (Vanzolini 1953) I once proposed that all specimens from the cerrados belonged to G. amarali Barbour, 1925, originally described from Engenheiro Dodt, Piauí, a town on the upper Rio Parnaíba, at the northeastern edge of the cerrados (Vanzolini 1976)
The main issue was thought to be the real nature of G. amarali
There being no authentic specimens of the form in Brasilian collections, I found it necessary to go to the type locality and try to obtain

Summary

INTRODUCTION

In a review of the genus Gymnodactylus (Vanzolini 1953) I once proposed that all specimens from the cerrados belonged to G. amarali Barbour, 1925 ( thought to be a subspecies of G. geckoides Spix, 1825), originally described from Engenheiro Dodt, Piauí, a town on the upper Rio Parnaíba, at the northeastern edge of the cerrados (Vanzolini 1976). The vegetation at Engenheiro Dodt (that was) and at Alto Parnaíba is cerrado Both localities (Map 1) are on or near the edge of the domain, close to the transition to the caatingas. Meristic characters (Table I): Dorsal tubercles in 13 – 16 irregular rows (mode 14, 72%); 31 – 49 tubercles in a paramedian row; 17 – 24 transverse rows of ventral scales; 13 – 21 infradigital lamellae on the fourth toe. Top of the snout moderately convex; in front of the level of the eyes covered with enlarged flat granules, behind that level with very fine granules interspersed with small button-like tubercles. Scales of the regenerated tail small, triangular, irregular, closely imbricate. 150 km: Ipueiras, Palmas, Peixe, Porto Nacional and Gurupí (centroid 1055, 4835), 13 specimens. A statistical definition of G. carvalhoi has to take into account its obvious geographical variation

MATERIALS AND METHODS

Findings

A N A LY S I S