E. complanata of the Amphinomidae order is identified as being a sister group to the Euphrosinidae order, a stouter bristle worm of relatively few segments (Figure 1). The Amphinomidae clade sits within the superclass Polychaete.
Recent studies using DNA sequencing has identified the cosmopolitan E. complanata species is comprised of at least three morphological species (Barosso et al , 2010). Further classification of these species is still pending, promoting continued treatment E. complanata as a single, broadly distributed, species.
Figure 1. Two differing phylogenetic relationships between errant polychates |