Hermaphroditic but some species possibly accompanied by complementary male; stalk distinct; capitulum with 5 calcareous plates, 5 or 2 reduced plates, or no plates; caudal appendages variable.
Results from a molecular phylogenetic analysis (Pérez-Losada et al., 2004) and larval morphology (Newman & Ross, 2001) suggest that the Lepadomorpha is distinguished from other members of the Thoracica. Buckeridge & Newman (2006) revised the taxonomy of stalked barnacles, rearranging Lepadomorph barnacles into a separate order, the Lepadiformes, which accommodates both suborders Lepadomorpha and Heteralepadomorpha, based on morphological similarities of the 2 groups. The separation of the Lepadiformes from the remainder of the Thoracica was further supported by a recent molecular analysis (Pérez-Losada et al., 2008). Foster (1978) considered the reduction of opercular plates in the capitulum to be a plesiomorphic character for stalked barnacles. However, molecular genetics in Pérez-Losada et al. (2008) showed that the Heteralepadomorpha is not ancestral, but has evolved at least twice from plated pedunculated barnacles. Revision of the systematics of heteralepadomorph barnacles requires further attention.