Article 43. Principle of Coordination.
43.1. Statement of the Principle of Coordination applied to genus-group names. A name established for a taxon at either rank in the genus group is deemed to have been simultaneously established by the same author for a nominal taxon at the other rank in the group; both nominal taxa have the same type species, whether it was fixed originally or subsequently.
43.2. Name-bearing types. When a nominal taxon in the genus group is raised or lowered in rank its type species remains the same [Art. 61.2.2] whether the type species was fixed originally or subsequently.