 Molecular phylogenetic trees based on mitochondrial genomic and nuclear ribosomal DNA sequence data indicate that "Antarctoneptunea" is closely related to the Northern Hemisphere genus "Kelletia", and "Penion" siphon whelks found in waters surrounding New Zealand and Australia.It has been suggested that some Antarctic fossil species of "Penion" are misclassified "Antarctoneptunea".Species within the genus "Antarctoneptunea" include