ZOOTAXA ISSN 1175-5326 (print edition) ISSN 1175-5334 (online edition) Accepted by M. Heinicke: 10 Dec. 2019; published: 29 Jan. 2020 207 Zootaxa 4729 (2): 207–227 https://www.mapress.com/j/zt/ Copyright © 2020 Magnolia Press Article https://doi.org/10.11646/zootaxa.4729.2.4 http://zoobank.org/urn:lsid:zoobank.org:pub:9C510AF7-2A80-4129-9ABF-47B162EDDA88 A new species of the genus Gonatodes (Squamata: Sauria: Sphaerodactylidae) from the western flank of the Cordillera Oriental in Colombia, with description of its hemipenial morphology ELSON MENESES-PELAYO 1,3 & JUAN P. RAMÍREZ 2 1 Grupo de Estudios en Anfibios y Reptiles de Santander (GEARS), Universidad Industrial de Santander, Carrera 27, Calle 9, Bucara- manga, Santander, Colombia. 2 Department of Biology, San Diego State University, San Diego, California, 92182, United States of America. 3 Corresponding author. E-mail: bioelsonp@gmail.com Abstract We describe a new sphaerodactylid lizard of the genus Gonatodes from the western flank of the Cordillera Oriental, Santander Department, Colombia based on morphological and molecular data. The new species is distinguished from all congeners by having a medium body size, by the absence of both a supraciliary spine and of clusters of distinctly enlarged conical scales on the sides and by having a subcaudal scale pattern (1’1”) and a cryptic dorsal color pattern in both sexes. Additionally, we describe for the first time the hemipenial morphology for a species of the genus. The new species increases the number of Gonatodes known from Colombia to eight and is the only known species of the country, as well as the second known mainland species of the genus not exhibiting sexual dichromatism. Key words: Molecular phylogenetics, morphology, hemipenial, taxonomy, sexual dichromatism Resumen Describimos un nuevo lagarto sphaerodactílido del género Gonatodes del flanco occidental de la Cordillera Oriental, Departamento de Santander, Colombia. con base en caracteres morfológicos y moleculares. La nueva especie se distingue de todos sus congéneres por tener un tamaño corporal medio, ausencia de espina supraciliar y de grupos de escamas cónicas ampliadas a los lados del cuerpo, por tener un patrón de escamas subcaudales (1’1”), y la presencia en ambos sexos de un patrón de coloración dorsal críptico. Adicionalmente, describimos por primera vez la morfología hemipenial de una especie del género. Con esta nueva especie aumenta el número de Gonatodes conocidos para Colombia a ocho, siendo la especie aquí descrita la primera conocida para este país que carece de dicromatismo sexual y el segundo caso para las especies continentales del género. Palabras Clave: Filogenia molecular, morfología, hemipenes, taxonomía, dicromatismo sexual Introduction The genus Gonatodes Fitzinger includes 31 described species of small sphaerodactylid geckos distributed from Southern Mexico to central Brazil and Bolivia and in both the Greater and Lesser Antilles (Uetz et al. 2019). Most of the species of the genus are diurnal and exhibit at least some degree of sexual dichromatism, in which males are more colorful than the drab females and juveniles (Rivero-Blanco 1979). The genus is known to be particularly diverse in Venezuela, as about three-fourths of the described species are found in that country (24 species, 72.7% of the entire genus; Uetz et al. 2019), with a considerable number of them described recently (11 of the 24 species of the country have been described since 2000, Uetz et al. 2019). The exceptional diversity of Gonatodes in Ven- ezuela contrasts with the depauperate richness of the neighboring country of Colombia in which only six species are known, all of them (except for the recently described Gonatodes riveroi Sturaro & Avila-Pires) being described