Re: SCIAM fossil bird article

[evelyn sobielski <koreke77@yahoo.de>]

> Teaser from the article
> 
> http://www.scientificamerican.com/article.cfm?id=winged-victory

I hope the wing is not of _Teviornis_ 
http://digitallibrary.amnh.org/dspace/handle/2246/2875

Because if so, the "widely held view of bird evolution" in question has been 
refuted since 2002, and cannot be said to be "widely held" for half a decade 
now... and given that there was a tendency to assign Hornerstown/Navesink/Lance 
Creek material to Charadriidae, Phalacrocoracidae, Procellariidae and whatnot 
(Hope reviews this nicely in her chapter in "Mesozoic Birds"), I wonder whether 
"Tertiary origin of modern birds" was ever a widely accepted theory.

Also interesting: http://digitallibrary.amnh.org/dspace/handle/2246/2812

So, either this is something really sensational - a Cretaceous crown 
hummingbird, perhaps... but after "Archaeoraptor", would such a major figure in 
the field as Dyke publish something so novel and ground-breaking in NG? Or it's 
just a few years late and has never been controversial, and more effort should 
be spent on determining *where* the K-Pg boundary runs through Neornithean tree 
than to setting straw men on fire.

For until now, I have not heard of anything beyond "higher waterbirds" from the 
Mesozoic. But of the latter, there seems to be quite a lot - fragmented, 
disarticulated material, mostly, and too plesiomorphic to recognize a "modern" 
lineage (think "neither albatross nor cormorant"). And the latter fact in 
itself is very illuminating. Crown Galloanseres can be safely inferred. For 
crown Charadriiformes, the case is also good. But even for crown "higher 
waterbirds", the case is weak.

Besides, some of the more outrageous "molecular-only" claims drag the origin of 
"near passerines" (Piciformes, Coraciiformes, Psittaciformes, Trogoniformes and 
Coliiformes) so deep into the Mesozoic that for the phylogeny to remain 
consistent, BAD itself gets into trouble. And this is a very bad thing, because 
the inferred molecular molehill should not overrule the factual fossil mountain 
of evidence.

So, while the Maastrichtian avifauna deserves intense scrutinity, Popper should 
not be thrown out of the window. Meaning: it should never be forgotten to 
ascertain, as much as this is possible, for what neornithean lineages there is, 
and remains, NO evidence from the Mesozoic.

It stands to note that the base of the "higher landbirds" is still molecularly 
unresolvable. One paper has claimed that there is no trace of an explosive 
radiation in that part of the (molecular) tree, but at least one other study 
(Galapagos finches, err tanagers) has shown that the molecular signature of 
explosive radiations is extremely hard to pin down: after a few Ma, the signal 
of genetic drift gets obliterated, so that only murky polytomies remain - and 
these can, by assaulting them with the right kind of math, be broken down into 
dichotomies. Whether these dichotomies are in any way a correct representation 
of the actual phylogeny is quite a different question...


Regards,

Eike