A hypothetical: a fully articulated _Megalosaurus_ is found - it has all the bits and peices used as the type specimen, but it also includes the rest of the skeleton, and the rest of the skeleton somehow shows it to be clearly not a descendant of the most recent common ancestor of _Triceratops_ and modern birds... yet _Megalosaurus_ was one of the two animals originally used to define Dinosauria...
I know distaste over the definition has been brought up and discussed in-depth before, but what i don't understand is something that those discussions seem to have taken as given: why the newer definition is accepted in the first place, how come "most recent common ancestor of _Triceratops_ and birds" has priority? Do the ICZN rules only apply after a certain date, or something similar? (serious question, it sounds like im being rhetorical here but really im not) Did Owen not publish in the right place? Or was there something in his wording... like an explicit definition based on characters and not relationships?