The past two decades have seen an increase in the documentation of reptile diversity
in the Australian arid zone through a combination of genetic and morphological analyses based on
widespread collections. Especially common are descriptions of new species of geckos, mostly
from rocky refugia, but also widespread terrestrial species as well. Here we focus on outstanding
taxonomic issues with the widely distributed diplodactylid Lucasium stenodactylus (Boulenger).
We analysed published and newly generated genetic sequences, especially from South Australia, to
resolve previous indications from morphology and molecular data that at least two other species may
exist within the current definition of L. stenodactylus. We found strong support for a Pilbara region
species, to which the name Diplodactylus woodwardi Fry applies, and for a new species occurring
mostly in South Australia, Lucasium microplax sp. nov. The Pilbara and South Australian lineages are
distinguished on numerous distinctive scalation and pattern characteristics and show deep genetic
divergences. The redescription of L. woodwardi adds yet another gecko species to the highly diverse
Pilbara region reptile fauna, and the description of the South Australian lineage as a separate species
from L. stenodactylus adds another widespread arid-adapted species to its reptile fauna.