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RE: Sereno's (2005) new definitions

David Marjanovic wrote:

> Given that a phylogeny is a *product* of character transformations, this
> approach is incongruous to say the least.  BCF keeps the topology, but
> re-writes the characters that were used to generate the phylogeny.

This seems to be based on a lack of understanding of how characters are
used to generate a phylogenetic hypothesis...

Oh dear. Don't let George hear you say that. He'll give you a serious ass-kicking. (Though I can't say I disagree with you, David.)

This is mainly good old parsimony-with-one-character (in this case the
number of phalanges in the 5th toe). This character is deemed to be
irreversible, no matter what the other characters say.


A beauty contest, in other words.  Winner takes all.

Yep -- but it will still be a troodontid (and probably a quite derived
one). That should be unambiguous enough for not harming its function as a
specifier.

Here's the problem... If a taxon is deemed to be a nomen dubium it becomes an invalid OTU, and so must be excluded from phylogenetic analyses. Therefore, its exact position in a phylogeny cannot be determined. I would think this would mean that the taxon in question would be invalidated as a specifier. Let's look at _Deinodon_. Although the hypodigm for _Deinodon_ is limited to the type teeth, we can still be pretty sure that _Deinodon_ is a derived tyrannosaurid. But we cannot demonstrate this hypothesis phylogenetically. To me, the usefulness of _Deinodon_ as a specifier is invalidated as a result. The same would be true for _Troodon_ if the hypodigm is limited to the type teeth. This problem could be sidestepped by designating an individual specimen of _Troodon_ as the specifier - like the type for _Stenonychosaurus inequalis_ (currently referred to _T. formosus_).

Good question. http://www.zhongwen.com | Search Dictionary | Pronunciation
only gives "bird" and "urine" as meanings of two different pronunciations
of "niao", so that should settle it.


My money's on "bird".

Cheers

Tim