So _Iguanodon_ is paraphyletic, huh? I wonder what would happen if you
threw _I. fittoni_ and _I. dawsoni_ into the mix...
On a nomenclatural note, if _I. atherfieldensis_ ceases to be congeneric
with _I. bernissartensis_, then _Heterosaurus_ and _Vectisaurus_ are
possible available names for this "new" genus - since _Heterosaurus
neocomiensis_ Cornuel, 1850 and _Vectisaurus valdensis_ Hulke, 1879 have
been considered synonymous with _I. atherfieldensis_ Hooley, 1924. To play
by the rules, the species names of both genera should have priority over
_atherfieldensis_, since they were named earlier. However, I understand
that both _H. neocomiensis_ and _V. valdensis_ might well be nomina dubia,
meaning that they cannot be regarded as synonyms of _I. atherfieldensis_.
Thus, a new genus name would have to be found for _I. atherfieldensis_,
should the genus _Iguandodon_ be shown to be paraphyletic.