Fig. 6.

Maximum likelihood ancestral state reconstruction of marginal musculature form for the Hydrozoanthidae portion of the composite evolutionary tree (Fig. 3c) populated by Hydrozoanthus and Terrazoanthus taxa. Drawings to the right of tree represent extant forms of the isolated mesogleal structures supporting the marginal musculature. Pie chart sections represent the relative likelihood of each character state (that exceeded 5 %) at the node and are enlarged at ancestral nodes to increase clarity