If you saw all those variants in the same paper, that seems like just
sloppy editing. I doubt if there is any implied difference in meaning or
emphasis, or that it has to do with how common the organism is.
Organizations like the Council of Biological Editors set standards for
things like this,
Dear Ecolog-Listers:
I came across a paper that renders the name and authorship of the Common
Green Iguana, as
*Iguana iguana *Linnaeus, 1758. Yet, other references have it as
*Iguana iguana *(Linnaeus, 1758). Finally, one has it
*Iguana iguana *(Linnaeus),1758
Is there an interesting story
