Simple answer : “a long time ago”.

More precisely, Louis Euzet used to teach is students, including me, that this decision was taken at an International Congress of Parasitology in Warsaw in 1971. Unfortunately, I do not have the paper at hand.

Anyway, use of terms such as “monogenetic trematode” after, say, 1975 was clearly a mistake and molecular phylogenies have later clearly and definitively demonstrated that the Monogenea are not part of the Trematoda.

Hi, I agree with Jean-Lou, since a while Monogenea is no longer considered part of Trematoda. You may revise Park et al. 2007 (A common origin of complex life cycles in parasitic flatworms: evidence from the complete mitochondrial genome of Microcotyle sebastis (Monogenea: Platyhelminthes)) and read the discussion on phylogenetic relationships among Neodermata.

Regards,

Antonio

Thank you so much Jean-Lou and Antonio Alejandro!!!!!

Jean-Lou, the Congress in Warsaw was held in 1971 or 1976? In 1971 it was the first Europenan International Congress of Parasitology in Rennes.

Juan Lucas.

ICOPA-IV in Warsaw was held in 1978 (19-26 August ).

Thank you so much Ruslan! Whas this decession published in a journal or proceedings late?

Juan Lucas Cervera.

In fact, Bychowsky has considered the monogenes as a class in 1937 in accordance with the proposal of Spengel (1905) that the group was more closely related to the cestodes and not a member of Trematoda! Bychowsky (1937) named the group Monogenoidea. Despite debates over the name, he was the first to officially recognize that this group of species were not members (an order) of Trematoda. The ICOPA "decision" was a vote to "choose" a name (in that case, Monogenea over Monogenoidea) and ignored the fact that Bychowsky has precedence on the decision of removing Monogenoidea from Trematoda. The iCOPA "decision" had nothing to do with the classification or phylogenetic position of the group. So, an@swering your question, Spengel was the first one to indicate that monogenes were not trematodes. Much before any formal taxonomic decision or voting of the preferred name.

Bychowsky, B.E. (1937) [Ontogenesis and phylogenetic interrelationships

of parasitic flatworms.] lzvestiya Akademiya

Nauk SSSR, Set. Biologiya, 4, 1353-1383. (In Russian: English

translation, 1981, Gloucester Point, Virginia: Virginia

Institute of Marine Science, Translation Series no. 26).

Spengel, J.W. (1905) Betrachtungen fiber die Architektonik

der Tiere. Zoologische Jahrbiicher, 8, suppl., 639-654.

Thank you so much!!!!!!

Juan Lucas Cervera.