Since 1998, American botanist Austin Mast and co-authors have been publishing results of ongoing cladistic analyses of DNA sequence data for "Banksia" and "Dryandra". Their analyses suggest a phylogeny that differs greatly from George's taxonomic arrangement. "Banksia aquilonia" formed a clade with "B. plagiocarpa", "B. oblongifolia" and "B. robur", rather than "B. integrifolia". Early in 2007, Mast and Thiele rearranged the genus "Banksia" by merging "Dryandra" into it, and published "B." subg. "Spathulatae" for the taxa having spoon-shaped cotyledons; thus "B." subg. "Banksia" was redefined as encompassing taxa lacking spoon-shaped cotyledons. They foreshadowed publishing a full arrangement once DNA sampling of "Dryandra" was complete; in the meantime, if Mast and Thiele's nomenclatural changes are taken as an interim arrangement, then "B. aquilonia" is placed in "B." subg. "Spathulatae".