Figure 1

External morphology of Remipedia and two hypotheses of their phylogenetic position. (A) Remipedia are composed of a cephalothorax and a homonomously segmented trunk consisting of numerous trunk somites equipped with biramous limbs (Photograph of Speleonectes tanumekes adapted from [22, 66]; photograph courtesy of J. van der Ham). (B) Because Remipedia have many characters that are considered plesiomorphic, for example the metameric trunk, they were seen as the basal sister group to all other Crustacea in early morphological studies (adapted from [13]). (C) In the last decade, several morphological and molecular analyses suggested Remipedia to be a more derived lineage within Pancrustacea (adapted from [8]).