The Code: First Reviser

There are cases where the same species was described twice within the same paper. Most commonly this happens when the workers are described separately from the queen and/or male. In these cases the names are synonyms and only one can be used, the other slipping into synonymy. But which name do we use?

The Code uses the Principle of Priority to decide which name becomes the senior synonym and is used and which becomes the junior synonym and goes away. In general the older name takes precedence and is used while the younger name becomes the junior synonym. There are exceptions to this rule, and "page priority" is one of them.

So what happens when two names for the same species appear in the same publication? They have the same date of publication and so Priority doesn't apply. And there is no such thing as "page priority", all pages within a publication are considered to have been published at the same time. In this case we use the Principle of the First Reviser.

The "First Reviser" is the first subsequent author who recognises a problem and publishes a solution. In the case of synonyms, the author is free to choose either name as the senior synonym, relegating the other to junior status. As long as these two names are considered to represent the same species (they are considered synonyms) then the actions of the First Revision must be followed.

For more detailed and technical explanations see the ICZN and Wikipedia.