Re: Ruben Strikes Back

["ekaterina amalitzkaya" <eamalitz@hotmail.com>]

> birds. It is >much< more likely that flight evolved in small archosaurs 
> that
> adopted an arboreal lifestyle and stayed small until true flight evolved in
> their clade, taking full advantage of light weight and gravity assist for
> gliding. The familiar theropods are much more likely to be large, 
> flightless
> descendants from various nodes along this lineage, and features such as

An interesting hypothesis- has it ever been published before? It is 
obviously not favored by most paleontologists.

However one thing is clear with this hypothesis- If we maintain that the 
flight is primitive for a subset of dinosauria, say theropoda then one must 
envision multiple losses of flight along each of the lines of theropods. 
This is obviously the least parsimonious explanation when compared to the 
conventional model. Further how would one devise a cladistic test for this 
flight loss hypothesis. I think it would be rejected based on the currently 
available fossils. At the best it may acceptable to suggest that the 
deinonychosaurs are secondarily flightless. If we accept that alverezsaurids 
are the dinosaur like birds then this flight loss model may have some role 
in the late  evolution of dinosaurs but probably not the early stages as 
speculated in the post by  Dinogeorge. While Dr. Holtz pointed out possible 
small early tetanurines what is the evidence that they- say Podokesaurus or 
Iliosuchus or ceratosaurs like procompsognathus had any remants of flight 
adaptations.

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