part_of part of part of develops from develops from ends during starts during inner fin epidermis tail surface structure fin crest xenopus_anatomy The thin epidermis extension of the inner fin visible in the mid trunk region of the inner fin at NF stage 27, and extending posteriorly and then ventrally, ending just before the proctodeum. The fin is more homogeneous in NF stage 46 tadpoles, and the inner fin and fin crest are no longer discrete. eriksegerdell XAO:0004229 NF stage 26 NF stage 46