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Phylogeny vs. taxonomy, and the Fighting Dinos exhibit at AMNH



Dear Tom

I just got back last week from a visit to Chicago and the UK, and ended 
up with an unplanned 24 hour layover in New York thanks to United 
Airlines. We shot into town and visited the American Museum of Natural 
History, and so we saw the Fighting Dinosaurs exhibit as well. I must 
say I was hugely impressed with the whole setup. We went to the Field 
Museum (e.g. Sue) and the Natural History Museum in London, and I felt 
the AMNH was the best (although the others are great!!). I was amazed 
to see all that undescribed material, and of course there are the star 
attractions of the nesting oviraptosaurs and the fighting Velociraptor 
and Protoceratops. The Saurischian and Ornithischian halls are well 
laid out and have excellent graphics. The former has a very lucid 
series of displays on bird evolution. My only gripe is that I was 
unable to photograph a lot of the specimens because of the perspex 
screens (which would reflect the flash), but of course that is not what 
the exhibits are designed for! It was like torture being dragged out of 
there by my wife to make it back to the hotel in time to check out! In 
the finish the only bit of New York we saw above ground was on the taxi 
ride back to JFK!

Getting back to bird origins, I have now tracked down the Jones et al. 
Longisquama article. I quote:

"Thus, we interpret the pinnate appendages of Longisquama as nonavian 
feathers, probably homologous to those in birds.

Archaeopteryx, the earliest known bird (145 Ma), possessed a complete 
plumage of flight feathers that differed little from those of many 
extant birds. Consequently, factors associated with earlier stages of 
feather evolution, the morphology of the earliest feathers, and the 
taxonomic groups in which they first occurred remain uncertain. 
Nevertheless, if Longisquama's integumentary appendages are homologous 
with those of birds, they may provide insight into an evolutionary 
grade through which feathers passed almost 75 million years before 
Archaeopteryx and perhaps before the origin of Aves itself."

When I wrote a while ago that I couldn't understand why Science 
published this article I was informed that it didn't really discuss 
bird origins. In other words, it was agnostic with respect to 
bird- non-avian theropod relationships. Well, what is the above? The 
statement "factors associated with earlier stages of feather evolution, 
the morphology of the earliest feathers, and the taxonomic groups in 
which they first occurred remain uncertain", especially in light of the 
recent Chinese discoveries, is at best disingenuous, and at worst 
downright misleading.

Having read the paper I stand by my earlier comment. Under normal 
circumstances (i.e. the interpretation of the fossil and the conclusion 
are highly equivocal and subjective), I do not believe Science would 
have touched a paper of this ilk with a barge pole. I can 
understand how frustrating this must be for Tom, Greg, and others!

Kendall

----------------------
Kendall Clements
k.clements@auckland.ac.nz