After all, just a thousand years ago there were a whole lot of similar modest sized moa species crawling around New Zealand.
DNA sez there were only nine moa species in total in the Pleisto- and Holocene, though with enormous sexual size dimorphism for *Dinornis maximus* (the big North Island species) and *Dinornis robustus* (the big South Island species).
Who knows how many gargantuavid (not sure if this is the family name, too lazy to check) species and genera were wandering around on the island/s (not sure how many there were, too lazy to check) of Campanian/Maastrichtian southern France. Must have been a number of them if that Darwin was right about evolution of the species.
Under which species concept(s)? Of course, Buffetaut & Angst didn't specify one either.
Chucking isolated material into a species is more often than not a very bad habit that we need to stifle yourselves on. Like tossing all Triceratops random bones into T. horridus when it now looks like there are two or more species separated stratigraphically.
Separated? My impression was they're continuous (according to Scannella and Fowler), with gradual anagenetic change, so that the questions become where _and if_ you want to draw lines -- in other words, which species concept to choose.