Molecular Phylogeny of the Astrophorida (Porifera, Demospongiaep) Reveals an Unexpected High Level of Spicule Homoplasy Cárdenas, Paco ; Xavier, Joana R. ; Reveillaud, Julie ; Schander, Christoffer ; Rapp, Hans Tore Abstract Publication: PLoS ONE Pub Date: April 2011 DOI: 10.1371/journal.pone.0018318 Bibcode: 2011PLoSO...618318C