On Aculifera: a review of hypotheses in tribute to Christoffer Schander

A review of the phylogenetic relationships among the major molluscan lineages, focusing on Aculifera (Polyplacophora, Caudofoveata, Solenogastres), is provided, centering on the newest developments in phylogenetic analysis of large molecular datasets in the light of the newest fossil discoveries. Support for the monophyly of Aculifera and Aplacophora is found among modern studies, and the anatomical implications for such relationships are discussed, but analyses of target-gene approaches often contradict this clade. The review is concluded with a discussion of the breadth and importance of the work of the late Christoffer Schander to molluscan systematics.