Fig. 1

Evolution of mitochondrial gene order in chitons. a Hypothesized gene rearrangements mapped onto our Bayesian phylogeny (Additional file 4). b Described chiton mitochondrial gene orders. The hypothesized ancestral order for chitons is based on outgroup comparison and it is also the most frequent among chitons. Genes (not to scale) are depicted as encoded either by the major (upper) and minor (lower) strand and abbreviations follow Boore [39]. Rearranged genes are colored and their inferred origin is shown onto the phylogeny a