Sand, stone, and Tropiocolotes: Diversity and distribution of dwarf geckos in Saudi Arabia

The genus Tropiocolotes comprises small geckos distributed across the Saharo–Arabian biogeographic realm, yet the taxonomy and distribution of several species, particularly those in Saudi Arabia, remain poorly understood. Historical confusion between T. nattereri and T. steudneri has been compounded by the recent description of T. yomtovi , a species morphologically very similar to T. nattereri , and the discovery of another genetically distinct lineage closely related to the two species. Here, we combine data obtained from recent field surveys in northwestern Saudi Arabia (Tabuk and Medina Provinces) with mitochondrial ( 12S and ND2 ) and nuclear ( c-mos and MC1R ) genetic markers to clarify species identities and assess the presence of cryptic diversity. DNA barcoding confirms that all newly collected material belongs to T. yomtovi , including populations previously assigned to T. nattereri . Mitochondrial genetic distances between the lineages are comparable to interspecific levels, and the haplotype network analyses revealed no allele sharing amongst the lineages of the T. nattereri group. Species distribution modelling further suggests that suitable habitats for T. yomtovi extend well beyond its currently known range. In addition to showing new data supporting the distribution of T. yomtovi in Saudi Arabia, we provide an overview of the Saudi endemic T. wolfgangboehmei , including a new record from approximately 200 km south of its type locality in central Saudi Arabia.