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Re: Campbell's even crazier than a MANIAC? (archeopteryx
So, agreeing to the ground-up theory, perhaps the most parsimonious thing to
admit is that birds had wings of scarce use for locomotion (using thier wings
for brooding or courtship), until they get the muscular mass necessary in their
pectorals to perform strong flight, without a gliding phase. If they could get
into trees (WAIR mediating) their flights might have been longer, but the
non-climbing state in the Paleognathae argues against this.
Indeed, apparently among the most basal Palaeognathae and Neognathae alive
(tinamous and galliforms) flight is short, and that might be the primitive
condition (but not in the also basal Anseriformes), and takes origin from the
soil. Perhaps all the Cretaceous birds were not better flyers than tinamous and
After all, it is true that based on the recent evidence, flight is more basal
than gliding for birds (e.g., tinamous and galliforms do not glide, but fly).
Now, with respect to retroversion of digit I, perhaps it has not so much to do
with perching as it might have to do with the generalised great angle between
all digits. There are fossils where even Archaeopteryx seem to have a
retroverted digit I, even if it cannot perch. Metatarsal I seems to be rather
freely attached to the rest, so assessing its position seems difficult to
It seems we arborealists have to capitulate to parsimony reconstruction, and
lack of arboreal adaptations.