I'm not an expert on geology, but one of the things that apparently happened somewhere subsequent to the development of Oncorhynchus was that Salmo became extinct in the Pacific basin—that is, they were here first.
Je ne suis pas géologue mais il paraît qu'après l'émergence de l'Oncorhynchus, le Salmo a disparu du bassin du Pacifique—là où il était apparu en premier.
