| The Gekkotan clade is a speciose and cosmopolitan group, with nearly 1500 members and constituents on six continents. Little known however are the pygopodids, the flap-footed geckos of the Family Pygopodidae (Gray, 1845). These gekkotans are limited to Australia (44 species) and New Guinea (2 species), but have diverged extensively into the most ecologically diverse limbless radiation save Serpentes, occupying a broad range of habitats and ecological niches. Current phylogenetic understanding of the family has relied almost exclusively on two works---Kluge (1974) and Jennings et al. (2003)---which have produced and synthesized an immense amount of morphological, geographical, and molecular data. However, current interspecific relationships within the largest genus Delma Gray 1831 are based exclusively upon a concatenated molecular dataset provided by two mitochondrial loci (16s, ND2), and a short segment (372 bp) of the nuclear protein-coding gene C-mos. Here, I reevaluate the inter- and intraspecific relationships within the genus Delma using two mitochondrial (16s, ND2) and four nuclear loci (Rag1, MXRA5, C-mos, DYNLL1), and identify points of strong conflict between nuclear and mitochondrial genomic data. We address mito-nuclear discordance, and resolve this conflict by recognizing several points of mitochondrial introgression as the result of deep hybridization events. Our results suggest a paraphyletic Delma australis group, from which we recognize two new species based upon morphological and molecular data. Additionally, while extensive morphological assessment of the genus has produced morphometric, osteological, and scutellation data, we add to the paucity of hemipenial descriptions of the family. Accurately assessing and addressing species richness and relationships within this endemic Australian Gekkotan genus is relevant for understanding patterns of squamate speciation across the continent. Identification of cryptic species lineages are vital to informed habitat protection and development, and cataloging local, Australian, and worldwide biodiversity. |
