Figure 4.

Different views in the interpretations of the host adoption within the neodermatan phylogenetic framework. The relative sequence in the acquisition of invertebrate/vertebrate hosts by three major groups of the Neodermata is illustrated by numerical order (not to scale). (A) 'Vertebrate first' hypothesis; (B) 'Mollusc first' hypothesis (modified [45]); (C) the interpretation of the present study.