Although first posited to be of a single origin, the two subfamilies of Phalangeriform marsupial possums (Phalangeroidea: cuscuses and brushtail possums and Petauroidea: possums and gliders) have long been considered, based on multiple sequencing studies, to have evolved from two separate origins. We reinvestigated these relationships by screening ~200,000 orthologous SINE loci across the newly available whole-genome sequences of Phalangeriform species and their relatives, and identified 106 highly reliable phylogenetic SINE markers. The presence/absence patterns of these SINE elements within the various Australasian possum genomes provide the first highly significant evidence for the reunification of Australasian possums into one monophyletic group.

Genome data were accessed in cooperation with Charles Y. Feigin. Genome TE extraction was performed via the multicomparative 2-n-way genome suite.