Lecanicephalidea

April 1995:

In the most recent revision of the group (Euzet, 1994), this taxon was considered to include 5 genera. Because of a lack of data, several other genera were considered as incertae sedis, or as genera inquirendae.
The total number of species was difficult to estimate, also because of lack of material and data.
Past records suggest the group parasitizes a diversity of rays.
The group had been allied with at least 4 different cestode orders: Euzet (1994) considered this taxon to have ordinal status as the Lecanicephalidea.
March 2000:
9 of the previously described genera are now considered to be valid.
5 new genera have been discovered.
The group is now thought to include approximately 35 valid species.
Lecanicephalideans are now known from almost all major groups of rays, as well as angel sharks and the megamouth shark and the epaulette shark.
Morphological and molecular phylogenetic analyses suggest the lecanicephalideans are a (more or less) monophyletic group within the order Tetraphyllidea.