Re: Strange thoughts on PN - was Re: BAD vs. BADD

[dinoboygraphics@aol.com]

Martin Baeker wrote:

> > > I think there is one very basic disagreement on what nomenclature is 
good for between us: From what you write (here and below),
nomenclature is used mainly by people talking about extinct animals and 
trying to reconstruct the history of life. However, biology (or
zoology) is a bit larger than paleontology. For most of zoology, it 
would not matter the least whether on single dog species evolved to a
flying monster or whatever, the grouping Canidae would still be useful 
99% of the time.<<<

Actually, my schooling was in zoology, not geology, and I follow the 
neontological literature as a matter of course; I suspect that most of 
the phylogenetic nomenclature guys (and gals) here are interested in 
extant animal groups.  Again canidae is a monophyletic group, whether 
it contains flying monsters or not.  Please provide an example of how a 
paraphyletic grouping is of more use to neontologists than a 
monophyletic grouping is.  Otherwise, the distinction you are trying to 
draw between disciplines doesn't appear to exist (in this case, 
anyways).

> > > And there is no morphological basis to claim that microraptor 
(assuming it is outside archae+passer) is meaningfully more unbirdish
than archaeopteryx. As Mike Taylor showed in his post, this argument 
cuts both ways.<<<

Huh?  How does it cut both ways?  I'm happy to follow that line of 
thought, because there is no obvious way in which other dromaeosaurs, 
trodontids, or oviraptors are significantly less birdish than 
Microraptor.  Congrats, you've just included all of maniraptora 
(including therizinosaurs, whose derived members don't look terribly 
birdish, but whose basal members do), and we could keep running that 
mind experiement all the way to the bottom of the eukarotic line, at 
which point the world would be very, very full of birds.

> > And always insisting on "birds are dinosaurs" will give people the 
impression that all dinosaurs are birdish, resulting in JP-type 
conceptions. Don't know if this is much better.<<

What kind of JP-like conceptions are you speaking of?  All dinosaurs 
ARE birdish compared to less derived archosaurs, and especially 
compared to squamates.  Obviously the further away you get from birds 
(but within dinosauria) the less birdish they tend to be, but still, 
compared to non-dinosaurian diapsids, even an upright, stiff-legged 
fast-growing hard eggshell laying Maiasaura is a lot more bird than an 
iguana is.

> > Then, why is any name useful besides of shortening a few sentences? 
Let's always say (passer+archae), (iguano+megalo) etc.<<

I'm sorry, I guess I wasn't clear; I'm not saying that naming itself is 
a useless convention, I'm saying that it appears that the confusion and 
extra work required to create, learn, and maintain a separate 
non-phylogenetic nomenclatural system waaaaay outways any obvious 
benefit for having said system.  Especially becaue we have yet to be 
shown a single situation in which a non-phylogenetic system is in fact 
more useful.

> > > So you do not recognise that a dipnoan looks much more like a trout 
than it does like a bird. I think that sharing lots of primitive 
characters, although useless in reconstructing a phylogeny, is still a 
recognizable feature that is useful.<<<

As has been pointed out, it's better to compare a dipnoan to 
Acanthostega than a bird, but even with a bird, it depends on what you 
are looking at.  If you mean that dipnoans and osteichthys both lack 
feathers, than sure.  But what if you are looking at mtDNA?  It's not 
just morphology that's of interest to neontologists.  What about brain 
organization?  Habitat? (should penguins be more closely related to 
fish than other birds?) Dermal color?  Respiration?

All of those are of interest to scientists studying extant organisms, 
and it certainly isn't obvious to me why one would ne inclined to 
eschew all of them (plus phylogeny) to make groups based on primitive 
morphology.  If there are practical examples, please share them.


Scott Hartman
Science Director
Wyoming Dinosaur Center
110 Carter Ranch Rd.
Thermopolis, WY 82443
(800) 455-3466 ext. 230
Cell: (307) 921-8333

www.skeletaldrawing.com

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