Monoclonius

[endocrin@desktop.com.au]

I've become rather confused about the status of Monoclonius. It doesn't seem
so long ago that some authors were trying their hardest to put Avaceratops,
Brachyceratops etc into Monoclonius, but recent postings to this list
suggest strongly that Monoclonius species are likely to be juveniles of
other ceratopian species. So, just what is the current position? If
Monoclonius is juvenile of other unknown species, is Monoclonius retained as
a genus until the "unknowns" are identified; does it become a nomen dubium,
or what? And why the change? Is it due to new material, or re-investigation
of old stuff (after all, Monoclonius material has been around for a long time)?
Graeme Worth