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Re: The ground-nowhere hypothesis on the origin of bird flight



I suppose I should say "wait for the papers!". Part 1 will be available soon. 
Part 2 should follow shortly after.

Of course, the talk at SVP was necessarily abbreviated. This was originally a 
50minute lecture, based on two forthcoming papers, compressed into 15 minutes 
at SVP. Part 1 was submitted for SVP2008 but was rejected, so I had to cram it 
all into a single talk for this year.

As for content... I really didn't want to cut the velociraptor slide from part 
2, or the piscivore slide from part1, but time constraints required it. In the 
paper(s) there's lots more discussion on the topics raised here on DML. I don't 
want to go into things in any detail until the papers come out.

I'm not saying that what we are proposing is THE answer, but it provides a 
whole new direction for research, and makes better sense of the peculiar 
anatomy of these critters, being based in real, commonly observed (and most 
importantly, directly testable) behaviours, not just hypothetical models.

 ----------------------------------
Denver Fowler
df9465@yahoo.co.uk
http://www.denverfowler.com
-----------------------------------



----- Original Message ----
From: Augusto Haro <augustoharo@gmail.com>
To: keesey@gmail.com
Cc: DML <dinosaur@usc.edu>
Sent: Thursday, 8 October, 2009 10:26:24
Subject: Re: The ground-nowhere hypothesis on the origin of bird flight

I just have a question by now with Fowler's hypothesis:

As far as I know, large unguals are restricted to dromaeosaurids among
paravians (as far as I know, troodontids and avialans have much
smaller claws), so it seems that killing subequally sized prey should
not be primitive for paravians, but just an apomorphy of
dromaeosaurids or a subgroup therein. So it seems difficult for me
that this predation mode can explain avian flight.

The paravian primitive condition seems to be a small ungual in pedal
digit II, perhaps for seriema-like killing of small vertebrates.

2009/10/8 T. Michael Keesey <keesey@gmail.com> wrote:

> Often when a new trait appears, it appears in great abunda
w inhibitors. Look at the
> earliest "apo-pterygotan" insects, with 3 pairs of  wings (one pair
> significantly smaller than the other two), or the earliest
> "apo-tetrapods", with 8 digits.

Agree with the insects and the correlations between intracorporal
homologues. However, the tetrapod polydactyly may represent a
reduction from an ancestral sarcopterygian condition with many more
rays than 8, as in dipnoans (if dipnoan fin rays are to be homologized
with digits, which appear likely; David Marjanovic may know better).