Fig. 5

Myosin gain and loss plotted onto the most widely accepted phylogenetic tree of the metazoa. Early metazoan evolution has been adapted from [70]. The mollusc and annelid orphan myosins have identical domain architectures as class-12 myosins but have not yet been classified due to their polyphyly in phylogenetic trees. Thus, the origin of the class-12 might be considerably older than currently assigned (solid arrow). The Mnemiopsis leidyi orphan might represent an extremely divergent class-1 myosin but could not unambiguously be classified because part of the motor domain is missing. The Amphimedon queenslandica orphan myosin contains a C-terminal Rap-GAP domain, which is only present in another orphan from Capsaspra owczarzaki. The classes were colored using the same color scheme as in Figs. 1 and 4