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Re: The dino-bird connection revisited
On Mon, 19 Feb 1996, King, Norm wrote:
> If _Protoavis_ did, and _Archeopteryx_ did not, might that suggest that
> _Archeopteryx_ is a flying theropod rather than a flying bird? That
> would surely explain why _Archeopteryx_ plots out very close to
Well... Yes. But if _Archaeopteryx_ is a "flying theropod," then the
very similar _Confuciusornis_ and _Sinornis_ are, too. And if THEY are
theropods (and not birds), then the same is true of _Concornis_,
Iberomesornis_, _Ambiortus_, and the enantiornithians. I think you can
see where I'm going with this one.
Suffice it to say, nowadays we really have a pretty good morphological
sequence of fairly well-preserved animals linking _Archaeopteryx_
securely with the modern birds. Hence, if _Archaeopteryx_ was not a
bird, then neither is a house sparrow.
> What is a bird, really? Can skeletal features provide a
> characterization, since feathers normally won't be preserved?
Certainly. Birds are fairly unusual critters. And practically every
skeletal peculiarity in birds can be traced to non-avian dinosaurs.
> Of course, if we assume that _Archeopteryx_ is a bird, that really stacks
> the deck in favor of maniraptoran ancestors for birds. What should I
> know that would show me why the claim of theropod ancestry for birds is
> not this transparently circular?
Non-archaeopterygian birds also show distinctly maniraptoran characters,
including the carpal block, deep coracoids, large sterna, and the form of
the hand. I particularly like the illo by Bakker in _The Dinosaur
Heresies_ of the hands of a hoatzin hatchling, _Archaeopteryx_, and
_Deinonychus_. Wow. Check it out.
> Norman R. King tel: (812) 464-1794
Pacific Lutheran University
Tacoma, WA 98447
"If you can't convince them, confuse them." -- Harry S Truman