We understand that particularly the case of Synechoccocus needs clarification and have thus extended the explanation there: “Sequences termed Synechococcus on the other hand were analysed together with sequences of the monophyletic clade Prochlorococcus, since Synechococcus is known to be a polyphyletic group and if all sequences (including a minimum of five lineages [36–38]) are taken together, Prochlorococcus has to be included, too”.
It follows from the whole article that the authors accepted the names (and also concepts) of taxa (mostly genera) from older literature, without necessary criticism. There are included revised genera according to modern methods together with taxonomically very problematic groups. As examples is possible to mention that Aphanizomenon ovalisporum and Anabaena bergii are really very related taxa, but they were already re-classified in one special and separate genus Chrysosporum. On the other hand, the complex “Prochlorococcus/Synechococcus” is still very unclear and surely is distant from the typical genus Synechoccocus. etc.