Molecular Phylogeny of Echiuran Worms (Phylum: Annelida) Reveals Evolutionary Pattern of Feeding Mode and Sexual Dimorphism Goto, Ryutaro ; Okamoto, Tomoko ; Ishikawa, Hiroshi ; Hamamura, Yoichi ; Kato, Makoto Abstract Publication: PLoS ONE Pub Date: February 2013 DOI: 10.1371/journal.pone.0056809 Bibcode: 2013PLoSO...856809G