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Troutman appears in part to be misunderstanding and misreading my statements
on indicators for preflight versus loss of flight in dinosaurs. I say that
secondarily flightless birds have very short tails because they are much
shorter than those of the earliest known flying bird, Archaeopteryx. All
flightless birds have larger sterna than the urvogel. I never said that
ossified sternal ribs are limited to flightless birds, Archaeopteryx did not
have them. Troutman's statement that all early birds have a sternum similar to
that of Archaeopteryx and Protarchaeopteryx is quite false, Archaeopterygiform
sterna are unique in their particular shape. The anterior indentation is not
for the coracoids, it is on the midline. Ratites have very small heads
relative to their bodies, smaller than in flying birds. Troutman's insinuation
that I need to look at more birds is misplaced. I have gone through the
Smithsonian's bird skeletal collection for the last 20 years. I've examined
the Archaeopteryx specimens. I have measured kiwi sterna. I suggest Troutman
examine more birds:)

A running protoflier that is not as close to birds as Archaeopteryx should be
less avian than the latter. Ergo it should have a shorter tail, or the urvogel
would have to reevolve a long tail. The protoflier should have a smaller
sternum without ossified sternal ribs because it does not have flight muscles
as large as the urvogel, or an air-sac complex as well developed. Since
Caudipteryx has some better developed flight related features than
Archaeopteryx, of the same sort seen in flightless birds, it is more probably
a secondarily flightless form than a protoflier.