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Re: Sheesh

----- Original Message -----
From: "evelyn sobielski" <koreke77@yahoo.de>
Sent: Tuesday, October 24, 2006 11:58 PM

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.

I'm not talking about the number of differences, I'm talking about the number of shared innovations. Confuciusornithidae and Neornithes share plenty of derived features that Archie and everything else lacks: short tail, pygostyle, at least partially reverted hallux, broadened 2nd finger for wing feather support, long, narrow coracoids, and so on.

Compare Gansus' shoulder/thorax
to Confuciusornis. If they were as close as
traditionally perceived, their LCA must have been not
very much after Archie;


So what.

I find Confuciusornis to be
adapted for flight better than Archie, but *not at
all* going into the direction of modern birds.


Why should it be -- it's not their ancestor.

The data set of Mayr et al analyzes no bird more
advanced than Confuciusornis, which is a major pity.


Yes (though less than the lack of some other taxa).

Thus, the relationship of Archie and C. with theropod
clades is resolved, but not that of modern birda with
either.


Not by that particular analysis.

> 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.


What is the connection between that and a dying star?

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.


There was a marine ecosystem collapse at the end of the Pleistocene???

2 Ma ago is a bit before its beginning, but I'm not aware of such a collapse at that time either.

Mass volcanism would be verifiable. 

Of course.

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)

The description of *Potamornis* (JVP December 2000): a quadrate and a few tarsometatarsi.