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Re: Greg Paul is right (again); or "Archie's not a birdy"



> ...and open the way for unjustified inferences in the other
> direction, where plesiomorphies are extrapolated too close to the
> crown.

 Curious to see some examples of this in the literature.

How about "cold-blooded-ness" and a body covering of scales being extrapolated all the way to the *Archaeopteryx* node?

Another examples I can think of (I don't have any literature here with me) is in art: before the discovery of *Eoalulavis*, enantiornitheans were depicted as lacking alulae.

> Is it really a good idea to maximize cross-disciplinary
> understanding at the expense of intradisciplinary understanding by
> making unneeded breaks with history? I'm all for bloody
> revolutions, but I don't like it when they're bloodier than
> necessary.

 I don't think this one is really that bloody, when you consider
 there is far more neontological literature on Aves than
 paleontological. I'll grant that it's bloodier than, say, Mammalia
 (where traditional paleontological usage was already close to the
 crown), which in turn is bloodier than the huge numbers of crown
 clades where the stem group is completely unknown (i.e., the majority
 of crown clades).

 Again, though, what makes "Aves" so exceptional? So far the best
 argument I've seen is its homonymy with a vernacular word in certain
 languages. I don't find that argument terribly compelling, either,
 since the vernacular word is also primarily neontological in usage.

Well, because one of these languages is Latin, Linnaeus simply called the birds "birds" (so he didn't have to invent a name like he did with Mammalia and Reptilia), and therefore the equation "Aves = birds" is stuck in the heads of pretty much everyone with an interest in biology.

And indeed, I cannot remember having ever read a statement like "all birds lack teeth" or "Aves is characterized by a toothless beak" even by a neontologist (after 1861 obviously). Neontologists of course don't think of Mesozoic birds much, but they do keep them in the backs of their heads and consider them "birds"/members of Aves. This is what Eike means by saying that neontologists do not use Aves as a crown clade name.

> But what if it is a vernacular name (like "birds") that is prone
> to unjustified inferences? The examples presented by Gauthier and
> de Queiroz (2001) all involved the term "birds", not _Aves_. You
> cannot get rid of unjustified infereces unless you convince all
> biologists that _Ichthyornis_ is not a "bird". Moving it out of
> _Aves_ is not enough.

 Could I convince biologists to avoid the term "bird" and use an
 appropriate alternative (avian, ornithuran, avialan, avipinnan,
 etc.) in technical discussions? (Or at least clarify what they mean
 by "bird"?)

I hope you can. I'm just pessimistic about it.

This holds especially for biologists who don't normally think about biodiversity. A few years ago we discussed the Nature paper about "the ancestral vertebrate karyotype", where Vertebrata was used instead of Osteichthyes, Tetrapoda instead of Sarcopterygii, and so on... it's not really about crown vs. bigger, it's about well-known vs. accurate.