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Re: Heterodontosaurid with protofeathers



On Thu, Mar 19, 2009 at 11:17 PM, evelyn sobielski <koreke77@yahoo.de> wrote:
>
>> 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.

Or possibly a larger clade of coelurosaurs if, e.g., _Sinosauropteryx
and _Dilong_ are not maniraptoriforms.

>>Â But, if either integument is homologous to
>> bird feathers, then Avifilopluma could be expanded to
>> include ornthischians (Avifilopluma=Dinosauria) and/or
>> pterosaurs (Avifilopluma=Ornithodira).
>
> Assuming either would happen - which name would apply?

All of them. Tim says "=" but should say "â" (or "=~" if that
character doesn't make it through). Since _Avifilopluma_ is
apomorphy-defined, it's extremely unlikely that it would turn out to
be the same as a node-defined clade like _Dinosauria_ or
_Ornithodira_, although it might have similar (or even identical)
known content. If feathers and ornithischian quills are synapomorphic,
then _Avifilopluma_ would include _Dinosauria_, and almost certainly
not equal it. If, in addition, "dino-quills" are synapomorphic with
"ptero-fur", then _Avifilopluma_ would include all of _Ornithodira_
(assuming that pterosaurs are stem-avians). In the unlikely event that
the apomorphy goes beyond the avian total group (i.e., that
crocodylians are secondarily "unquilled" -- apologies to
_Unquillosaurus_), then _Avifilopluma_ becomes a synonym of _Panaves_
or _Pan-Aves_ or whatever the avian total group is named.

Of course, no code governs the definition of any of these names yet,
so it's all fair game.
-- 
T. Michael Keesey
Technical Consultant and Developer, Internet Technologies
Glendale, California