Re: Sheesh

[evelyn sobielski <koreke77@yahoo.de>]

> I think you've misunderstood. If anything is removed
> from Aves (...I 
> wouldn't call that sensu stricto...),

Yea, my bad.

> old Archie, not 
> *Confuciusornis*, which nobody doubts is more
> closely related to Neornithes 
> than Archie is.

Hmmm... skull, wings, tail... it has a toothless beak,
but that is not an a, but the entire mode of flight
was decidedly non-neornithine. I'd rather say neither
is particularly close. Compare Gansus' shoulder/thorax
to Confuciusornis. If they were as close as
traditionally perceived, their LCA must have been not
very much after Archie; I find Confuciusornis to be
adapted for flight better than Archie, but *not at
all* going into the direction of modern birds.

The data set of Mayr et al analyzes no bird more
advanced than Confuciusornis, which is a major pity.
Thus, the relationship of Archie and C. with theropod
clades is resolved, but not that of modern birda with
either. When I first saw Spindler's reconstruction of
the short- and long-tailed Confuciusornis in flight, I
immediately thought "WTF wings?! WTF tail!". These
birds flew like an arrow, steered like a cow, and had
a lukewarm wingbeat. An alula would have been entirely
wasted on them. Swifts are the closest modern
approximation in aerodynamic shape.

> > the "Late Pleistocene supernova" theory
> 
> Never heard of that! Please explain. :-o

An OB association (group of nascent stars) passed Sol
system c. 2 mya. Supernova activity would have caused
global ozone depletion on a massive scale, which is a
good underlying cause for the end-Pleistocene pattern
of marine ecosystem collapse. No firm evidence, but
that there was a minor mass extinction seems verified
as far as I can see and that it inordinately affected
marine life is fairly sure.
Mass volcanism would be verifiable.

> There are fragments in the Lance Formation which
> extends all the way to the 
> K/Pg boundary.

Ah good! Do you have a source? (I remember reading in
a fairly recent paper there weren't)

Regards,

Eike




                
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