A Phylogenetically Important Lygosomine Skink Resurrected from Taxonomic Obscurity: Lygosoma unilineatum de Rooij, 1915

Abstract

Lygosoma unlineatum de Rooij 1915 is a large New Guinea skink known from five specimens. It was previously associated with taxa now considered to be in the Sphenomorphus group of lygosomine skinks. However, it is a member of the Eugongylus group of lygosomines, best placed in the relatively primitive genus Eugongylus. Within the Eugongylus group, the species has two unique primitive characters: nine premaxillary teeth (versus 211) and pterygoid teeth. The species also has one unique derived character: fusion of the first supralabial and the nasal scale. The two primitive characters make the species especially important in reconstructing the phylogeny of the Eugongylus group.