The reduced limbed lizards of the genus Bachia (Reptilia, Squamata, Gymnophthalmidae); biogeography, cryptic diversity, and morphological convergence in the eastern Caribbean

Abstract

The phylogenetic and systematic relationships of the reduced limbed lizards of the genus Bachia are poorly understood. Here, we investigate the eastern Caribbean Bachia assigned to the B. heteropa and B. flavescens groups, whose members are characterized by a band of hexagonal or quadrangular scales on the dorsum, respectively. The polytypic Bachia heteropa is redefined, and the previous subspecies in the Grenadines (Bachia heteropa alleni) and Trinidad (B. h. trinitatis) are demonstrated to be species-level lineages. One new species of hex-scaled Bachia was formerly assigned intergrade status between B. heteropa and Bachia trinitatis. Here, it is described as a new species from Caripito, Venezuela. Bachia h. heteropa, B. h. lineata, and B. h. marcelae are elevated to species status. The Tobago species formerly considered a member of the Bachia flavescens species group is described as a new species. In this paper, we increase the number of species in the genus Bachia from 25 to 31 with the description of two new species and the elevation of four previously described species from the synonymy of Bachia heteropa. This work will greatly improve the understanding of the systematics and evolution of Bachia in the eastern Caribbean.