Long forsaken species diversity in the Middle American lizardHolcosus undulatus(Teiidae)

Abstract

Numerous reptile species have been divided into subspecies. Although this classification may capture the morphological variation within species, it often conceals significant species diversity because many subspecies actually represent species under lineage-based species concepts. The lizard Holcosus undulatus is a common, widely distributed, monotypic species in Middle America. However, 12 subspecies of this taxon were recognized until the early 1970s. We used two lineage-based methods for species delimitation to re-evaluate species limits within H. undulatus with DNA sequence and morphological data. We included all the previously recognized subspecies of H. undulatus except H. u. miadis. Holcosus undulatus was exclusive. In addition, H. u. amphigrammus, H. u. gaigeae, H. u. hartwegi, H. u. parvus, H. u. pulcher, H. u. sinister, H. u. stuarti, H. u. thomasi and H. u. undulatus were supported as distinct evolutionary lineages based on the molecular and morphological evidence. We therefore elevate all of these subspecies to species rank. In addition, two separate mitochondrial lineages may represent cryptic, undescribed species within H. undulatus. The morphological distinctness and allopatry of H. u. miadis and H. u. pulcher, as well as the high genetic divergence of the latter species, suggest that they also represent distinct evolutionary species. Our results also suggest that additional species diversity may still be hidden within the H. u. amphigrammus, H. u. parvus, H. u. sinister and H. u. undulatus lineages. This work supports resurrection of overlooked diversity within Holcosus, which has important implications for the conservation of this genus in Middle America. © 2015 The Linnean Society of London