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

Abstract

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.

Keywords:

• Polyplacophora
• Caudofoveata
• Solenogastres
• Mollusca
• Monoplacophora
• phylogeny
• fossils

Acknowledgments

I am indebted to Julia Sigwart and Christiane Todt for their invitation to participate in the Aculifera symposium of the Ponta Delgada World Congress of Malacology. Dave Lindberg and an anonymous reviewer provided constructive criticism that helped improve upon an earlier version of this paper. This is a contribution to the collection Who are the ‘Aculifera’? in memory of Christoffer Schander.