Re: ABSRD BAND on Sinornithosaurus feathers

["Ken Kinman" <kinman@hotmail.com>]

Thomas,
     Since you are interested in what tunes the ABSRD BAND might be singing 
in response to the Sinornithosaurus paper, here is a posting by a very vocal 
(but anonymous) member of that group (from sci.bio.paleontology):

   "Having read the paper, I would say that the authors have not succeeded 
in showing that Sinorithosaurus has feathers. Unlike what Jones et al. did 
with Longisquama feathers, Xu et al. have not shown that Sinornithosaurus' 
integumentary structures have a hollow core, a calamus, or pulp caps. They 
have not shown that these structures are follicular in origin. Unlike 
Caudipteryx, there is also no evidence that Sinornithosaurus has wing 
feathers. The model of feather development proposed by Prum, and illustrated 
in fig. 6 of this paper, also makes no adaptive sense. If every stage in the 
evolution of a morphological structure has to be adaptive, then it is 
difficult to fathom how a simple hollow cylinder or a pine needle-like 
branching structure can be functional in an animal.
    It is also much easier to evolve the intricate interlocking barbules of 
avian feathers from a solid sheet (in other words from the type of feathers 
with solid vanes found in Longisquama) through a process of weight reduction 
than it is to build the vane up from a clump of loose filaments. Insects, 
bats and pterosaurs fly with membrane wings, so a solid sheet is the norm 
for wings; bird wings are also functionally solid sheets. It is therefore 
foolhardy to fly with wings made from interelocking filaments, not knowing a 
priori whether the interlocking structures are strong enough or structurally 
sound enough to serve functionally as wings. To paraphrase Feduccia, such 
attempts by a theropod to fly may result in a grease spot on the ground. It 
makes more sense for a volant animal to glide and then fly with solid sheets 
of feathers and for some descendants of such animals to then experiment with 
weight reduction methods that would not compromise either the strength or 
the structural integrity of the wings. Those that succeeded with weight 
reduction would then be more fit since it will drastically reduce the amount 
of energy needed to fly.
    It is interesting to note that some cladists (in the recent debate in 
Science; thanks to Rick Toomey for calling attention to that issue) argue 
that Longisquama does not have feathers despite the fact that such features 
as hollow core, calamus, pulp caps and follicular origin have been 
demonstrated by Jones et al. Yet other cladists are willing to believe that 
Sinornithosaurus has feather homologs despite the fact that none of these 
features found in both avian and Longisquama feathers has been found in 
Sinornithosaurus' integumentary structures. It is quite obvious that the 
cladists are influenced primarily by their cladograms, rather than by the 
structural similarities between avian feathers and Longisquama feathers. 
Lastly, Sinornithosaurus simply lived too late to have anything to do with 
feather origins. In sum, this paper is interesting speculation, but little 
else."

**********************************************************
> From: "Thomas R. Holtz, Jr." <tholtz@geol.umd.edu>
> Reply-To: tholtz@geol.umd.edu
> To: "dinosaur" <dinosaur@usc.edu>
> Subject: Martin on Sinornithosaurus feathers
> Date: Thu, 15 Mar 2001 09:56:41 -0500
>
> Greetings,
>
> For those interested, I have come across the first reference so far from 
> the
> anti-dinosaurian origin of birds group.  In an online Science News article
> (URL is:
> http://sciencenow.sciencemag.org/cgi/content/full/2001/307/3) (you may need
> an online subscription to Science to see this: I'm not certain), Martin
> states:
>
> "They certainly do not tangle like wet down feathers."
>
> As far as I've seen, that is it from Martin and the BAND.
>
>               Thomas R. Holtz, Jr.
>               Vertebrate Paleontologist
> Department of Geology          Director, Earth, Life & Time Program
> University of Maryland         College Park Scholars
>               College Park, MD  20742
> http://www.geol.umd.edu/~tholtz/tholtz.htm
> http://www.geol.umd.edu/~jmerck/eltsite
> Phone: 301-405-4084    Email:  tholtz@geol.umd.edu
> Fax (Geol):  301-314-9661      Fax (CPS-ELT): 301-405-0796
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