Abstract
The lowland region of Sumatra Barat has received little attention in previous biodiversity studies. Past studies have mainly focused on highland habitat and conservation areas. However, many populations of Cyrtodactylus in the lowland habitats of Sumatra Barat were not correctly identified. A phylogenetic tree based on the NADH dehydrogenase subunit 2 (ND2) gene showed that the lowland Sumatran population is the sister group of the Malaysian lowland species, C.semenanjungensis, together nesting within the agamensis group. The genetic divergence within the Sumatra Barat population is 0-4.2% and 18.3-20% to C.semenanjungensis. Further examination of morphological characters revealed that they differed from the sister clade and other Sumatran Cyrtodactylus members by a unique combination of characters such as absence of tubercle on brachium, presence of tubercle on ventrolateral fold, 32-41 paravertebral tubercles, 38-46 ventral scales, enlarged femoral scales, presence of precloacofemoral pores and 22-23 subdigital lamellae under fourth toe. Based on the morphological and molecular evidence, the lowland Sumatran population is herein described as a new species, increasing the number of species in Sumatra to seven. More comprehensive and intensive sampling efforts would most likely yield further discoveries in the group of Sumatran Cyrtodactylus in the near future.