Fig. 1

Simplified phylogenetic tree of the major annelid taxa based on recent phylogenomic studies [1, 6,7,8,9,10,11,12,13,14,15]. In the lineages leading to terminals, characteristics of adult cerebral eyes are included [16,17,18,19,20,21,22]. Note that a given character state is not necessarily present in every member or subgroup of this clade