* Special staining and clearing techniques make it possible to interpret the organization of complex structures & the ratherm obscure & ephemeral events of the sexual cycle
* Without exceptions to date, molecular phylogenetic analyses seem to highlight the evolution of the earliest stages in the development of the female apparatus and associated cells.
* The molecular-based phylogenies each provide an independent test of classification to the one based on morphological or ultrastructural evidence.
* Besides elucidating relationships, phylogenetic hypotheses inferred from gene sequence data provide the critical framework for studies of morphological character evolution and life history evolution