Phylogenetic tree based on mitochondrial COI sequences. Numbers by branches show bootstrap values (Maximum Likelihood analysis) and posterior probabilities (Bayesian analysis). Only significant numbers (>80% and >0.9) are indicated. Onchidella, Peronia, Peronina, Platevindex, Onchidium, Onchidina, and Melayonchis sequences serve as outgroups. Numbers for each individual correspond to unique identifiers used for DNA extraction. All sequences of Wallaconchis specimens are new, except two sequences obtained from GenBank (from specimens from China). Information on individually-identified specimens can be found in the lists of material examined and in Table 1. The color used for each species is the same as the color used in the other trees (Figs 2–5) and on the map of species distribution (Fig. 6).