We collected two specimens of an undescribed species of Lygosoma from pitfall traps in an urban rainforest in Kuching and from the base of a forested hill in western Sarawak, East Malaysia. The new species is diagnosable from all south-east Asian congeners by morphological characters, and most closely resembles Lygosoma herberti from the Thai-Malay Peninsula. The new species shows substantial molecular divergence from its closest relatives in two protein-coding genes, one mitochondrial (ND1) and one nuclear (R35) that we sequenced for several south-east Asian congeners. We describe the new species on the basis of this distinct morphology and genetic divergence. It is the third species of Lygosoma known from Borneo, and highlights the continuing rise in lizard species diversity on the island. In addition, the discovery of this species from a small urban rainforest underscores the importance of preserving intact rainforest areas of any size in maintaining species diversity.
An integrative taxonomic analysis of Subdoluseps herberti from southern Thailand and Peninsular Malaysia and S. samajaya from Sarawak, East Malaysia (Borneo) recovers the former as paraphyletic with respect to the latter. The analyses recover the three southernmost populations of S. herberti in Peninsular Malaysia as conspecific and the sister lineage of S. samajaya, whereas S. herberti from Thailand and northern Peninsular Malaysia constitute the sister species to S. samajaya plus the southern three Peninsular Malaysian populations. As such, the southern populations are described herein as S. malayana sp. nov. and all three species are referred to as the S. herberti group. Clade boundaries and breaks within this group on the Thai-Malay Peninsula occurring at the Isthmus of Kra, across the Kangar-Pattani line, and between the Thai-Malay Peninsula and Borneo are consistent with phylogeographic patterns of other Sundaic taxa. The discovery of S. malayana sp. nov. continues to underscore the fact that, despite the well-studied nature of the lizard fauna of Peninsular Malaysia, much of it still remains unrealized and for conservation efforts to move forward, field research followed by expeditiously revised taxonomies must continue.