Re: Heterodontosaurid with protofeathers

["David Marjanovic" <david.marjanovic@gmx.at>]

> > the entire concept of "Dinosauria" would be meaningless anyway,
> > so the taxon would collapse.
>
> Yeah, it would collapse. But collapse is not a kind of stability.

In a sense it is: if the name doesn't refer to anything that's similar to 
the concept that's historically associated with it, it's good if it 
self-destructs, because that means it's associated either with more or less 
the same concept or with nothing at all.

> Someday I will test the stability of some definitions - cladistic and
> non-cladistic ones - in a retrospective manner. Let's say, if we apply
> the _Passer domesticus_ + _Triceratops horridus_ definition of
> Dinosauria back into 1889 how would be their tree topology (a tree
> constructed with phylogenetic analysis and the characters state as
> known at that time)?

Phylogenetic analysis did not exist back then. Phylogenetics was not a 
science back then*, it was an art. -- Also, what would your exercise be good 
for?

* Except arguably in linguistics.