There is no reason to deny a natural sequence or to split off genera only to have to attempt later to re-insert them into the whole by means of subordos andsuperfamilies.
1978, Philip D. Gingerich,New Condylarthra (Mammalia) from the Paleocene and Early Eocene of North America, page289:
The genusSaipanetta has been suggested to be a surviving relict of the metacopidansuperfamily Healdiacea because of its muscle scar pattern and narrow duplicature; nevertheless, it differs from the Metacopida in its more complex hingement, lack of a distinct contact groove, exaggerated domiciliar asymmetry, and lack of posterior ridges or angulations.
(molecular biology) A large group of related proteins or other molecules.
