The hidden diversity and inland radiation of Sri Lanka’s ground-dwelling geckos of the genus Cyrtodactylus (Reptilia: Gekkonidae)

Abstract

The genus Cyrtodactylus has recently been classified phylogenetically into several clades, subclades, groups, and some into Sri Lankan Cyrtodactylus. Certain complexes from the Indian subcontinent have been assigned to the “C. triedrus group”. This group is comprised of medium-sized species (SVL 50.6–105.7 mm) and are composed of five major species complexes: fraenatus, triedrus, deccanensis, jeyporensis, and collegalensis. Among these complexes, the latter four are composed of ground and litter dwelling species, which were previously assigned to the genus Geckoella; and is currently being treated as a subgenus. Cyrtodactylus triedrus, an endemic species of Sri Lanka, has long been considered a widely distributed single species in this part of the world. Based on morphological and phylogenetic evidences, we demonstrate that C. (G.) triedrus is not a single species, but a species complex. We also describe a new species that is restricted to intermediate savanna-mixed dry lowland forested habitats. Furthermore, we resurrect Geckoella punctata, assign it to the genus Cyrtodactylus and designate a lectotype that we redescribe. The genetic divergence across species of the C. triedrus clade varies between 11–26% in the studied fragment of the mitochondrial NADH dehydrogenase subunit 2 gene. The molecular phylogeny of the ground dwelling radiation of the subgenus Geckoella indicates deep splits between the Indian species and Sri Lankan endemic C. (G.) triedrus sensu stricto, and between Indian dry and wet zone clades. Cyrtodactylus (G.). triedrus is restricted to the moist or submontane forests in the Central highlands of Sri Lanka and is redescribed herein based on its holotype.

http://zoobank.org/urn:lsid:zoobank:org:pub:3B37037C-EE9F-4011-BEC9-47E1F3BB6779

Key words:

• biogeography
• cryptic species
• Geckoella
• island
• new species
• phylogeny
• systematics

Acknowledgements

We thank the department of wildlife conservation and the department of forestry of Sri Lanka for providing collecting permits (Permit nos. WL/3/2/42/18–21 and R&E/RES/NFSRCM/2019-04) to SK, ADS, and K.D.B. Ukuwela (Rajarata University of Sri Lanka). N. Wickramasinghe (former director), S. Kasthuriarachchi (director), L. Somaratne, C. Kothalawala, C. Munasinghe, T. Gamage, R. Dasanayake, T. Dasanayake R. Wickramanayake, P. Gunasiri, and all the staff (employed since 2005) at NMSL are acknowledged for facilitating the in-house study of specimens under their care. K.D.B. Ukuwela, N.H. Perera, S. Wickramarachchi, and N. Karunarathna are acknowledged for the assistance in the field, and Sanjaya Bandara for proof reading. ZAM thanks the Singinawa Conservation Foundation and National Centre for Biological Sciences for the support. Finally, we also thank R. Somaweera (Australia), J. Supriatna and the staff of the Research Center for Climate Change, University of Indonesia, for their support.

Disclosure statement

No potential conflict of interest was reported by the author(s).

Supplemental material

Supplemental material for this article can be accessed here: https://doi.org/10.1080/14772000.2022.2039319.

Associate Editor: Dr Susan Tsang