Fig. 7

Reconstructed relationship of some groups within the isopod group Cymothoida with a schematic character evolution of the mouthparts and thoracopods. Color-marks: labrum = purple, mandibles = blue, paragnaths = orange, maxillula = cyan, unclear mouthpart = white, maxilla = yellow, maxilliped = green, first free thoracopod = red, claw-like dactyli on thoracopods = dark orange. Important steps are: 1) cirolanid-like ancestor with carnivorous mouthparts, swimming thoracopods; 2) modified mouthparts for piercing, maxilliped and first free thoracopod modified for attachment; 3) mouthparts forming a sucking mouth cone, three thoracopods modified for attachment; 4) sucking mouth cone, all seven thoracopods modified for attachment; 5) mouthparts elongated still forming a mouth cone for piercing, reduced mandibular palp and maxillula, reduced seventh thoracopod. Position of Urda either in position A or B (see discussion)