Phylogenetic relationships in the Eugongylini (Squamata: Scincidae): generic limits and biogeography

Skinks (Family Scincidae) are the most diverse family of lizards (similar to 1745 described species worldwide), and the Australasian region (Australia, New Caledonia, New Zealand) is a recognised global hotspot (>600 species) for skinks. Here we focus on determining the phylogenetic relationships and biogeography within the tribe Eugongylini, one of three lineages in the region. We used mtDNA (ND2) and nuclear (RAG-1, c-mos) DNA sequences and phylogenetic analyses to reveal the presence of three well-supported lineages of Australian Eugongylini. We found a sister relationship between the monotypic genera Eroticoscincus and Harrisoniascincus, and that the monotypic Anepischetosia has close affinities with Carinascincus coventryi and Pseudemoia. C. coventryi represents a separate lineage from the main Carinascincus radiation. Emoia was not found to be monophyletic, with Emoia s.s. part of an Australian lineage, and the remainder of the genus representing an older divergence within the tribe. The widespread and speciose Cryptoblepharus represented a well-supported lineage within an Australian lineage. Our analyses confirm previous suggestions that four Sphenomorphus species (louisiadensis, minutus, bignelli, and aignanus) are misplaced, and are part of the Eugongylini. Our phylogenetic analyses support the hypothesis that the origin of the tribe lies in Asia, with dispersal events to Africa, Australasia, and Oceania.

Automated summary

Skinks are the most diverse family of lizards and the Australasian region is a hotspot for skinks. This study focused on determining the phylogenetic relationships and biogeography of the Australian Eugongylini tribe. By analyzing genetic sequences, three well-supported lineages of Australian Eugongylini were identified, and some new relationships were revealed.