A chemical view of the most ancient metazoa – biomarker chemotaxonomy of hexactinellid sponges Model Digital Document Thiel, Volker Blumenberg, Martin Hefter, Jens Pape, Thomas Pomponi, Shirley A. Reed, John K. Reitner, Joachim Worheide, Gert Michaelis, Walter Publisher Springer-Verlag Member of HBOI Faculty Contributions