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Re: Heterodontosaurid with protofeathers
Mike Keesey wrote:
> Well, if shifting or uncertain content = "danger", then
> nomenclature may not be your cup of tea, anyway.
I have nothing against PN. Quite the opposite. PN is my system of choice, and
I much prefer it to rank-based classifications (phylum, class, order... etc).
I'm only picking on apomorphy-based clades. Look at Avifilopluma:
"The clade stemming from the first panavian with feathers homologous with those
of Aves ... feathers referring to hollow-based, filamentous, epidermal
appendages produced by follicles."
Are the epidermal filamentous structures seen in _Tianyulong_ and/or pterosaurs
homologous with feathers? The content of Avifilopluma hinges on this question.
The content is not just in flux because of topology (as in stem- and
node-based clades), but homology as well.
If the "dinofuzz" of _Tianyulong_ and the "pterofuzz" of pterosaurs like
_Sordes_ is NOT homologous to bird feathers, then the Avifilopluma would be
limited to maniraptoriform theropods. But, if either integument is homologous
to bird feathers, then Avifilopluma could be expanded to include ornthischians
(Avifilopluma=Dinosauria) and/or pterosaurs (Avifilopluma=Ornithodira).
> That said, your example still holds, but you wouldn't have
> to give _Dinosauria_ a qualifying clause if you just established
> that the name _Archosauria_ has priority for Clade(_Crocodylus
> niloticus_ + _Vultur gryphus_) (or whatever).
True. But what's the harm in including a qualifying cause? That means the
definition of Dinosauria is self-contained, and doesn't need recourse to other
definitions (such as that for Archosauria).