Complex sentence: The Peniculids were first defined by Fauré-Fremiet in 1956, as one of three suborders of hymenostomes, which are now treated as subclasses of the Oligohymenophorea.
Split into simpler sentences: The peniculids were first defined by Fauré-Fremiet in 1956. Originally they were one of three suborders of the hymenostomes, which are now treated as subclasses of the Oligohymenophorea.