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Re: Feduccia et al. (2005) Critique



Banded pigmentation is also occasionally found in the bird feathers from
the formation, so if the non-avian dino integument is collagen rather
than keratin, then Feduccia must come up with an explanation as to why
color banding would evolve in a tissue that is hidden from view on a live
animal.  Or he must come up with a taphonomic explanation that doesn't
involve a lot of arm-waving.

I'd like to see a rigorous geochemical study done on the pigmented
segments vs the non-pigmented segments on these specimens.  It would be a
destructive analysis, but very little material would be needed.

<pb>
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On Mon, 17 Oct 2005 18:41:48 -0400 Jon Barber <augray@sympatico.ca>
writes:
> At 02:25 PM 10/11/2005 +0000, Michael Mortimer wrote:
> >The BAND movement simply refuses to die, invigorated as it is by 
> its 
> >transformation into MANIAC.  It seems like just yesterday that I 
> shot down 
> >Martin's latest publication 
> (http://dml.cmnh.org/2005May/msg00317.html), 
> >now I get to do the same for Feduccia's.  Well, technically 
> Lingham-Soliar 
> >and Hinchcliffe are coauthors, but I mostly refer to Feduccia 
> himself 
> >below for simplification.
> >
> >Feduccia, A., Lingham-Soliar, T., and Hinchliffe, J.R. (2005). Do 
> >feathered dinosaurs exist? Testing the hypothesis on neontological 
> and 
> >paleontological evidence. J. Morphology (in press).
> >
> >
> >The article starts out with an introduction full of fun 
> inaccuracy.
> 
> [big snip]
> 
> >When it comes to Sinornithosaurus' holotype, it's hard to see where 
> 
> >Lingham-Soliar is going.  No doubt affecting this is the fact the 
> figure 
> >is hopelessly blurry.  He claims the base of the illustrated tuft 
> of 
> >filaments is actually an eroded area with filaments that run 
> diagonal to 
> >the main tuft.
> 
> This *may* be a second tuft hidden in the matrix under the first.
> 
> >  Perhaps true (I can't evaluate the figure), but Xu et al. (2001) 
> 
> > mentioned several instances of tufts.  Lingham-Soliar argues a 
> case of 
> > filaments branching from a central one is due to the "laws of 
> chance", 
> > which is fine, but again Xu et al. stated several of these 
> occurances 
> > were present.  He also states that integumentary structures are 
> found 
> > throughout the substrate, including fainter (more eroded?) ones 
> covering 
> > almost the entire surface.  I don't see how this argues against 
> them 
> > being feathers.
> >Given the quality of Lingham-Soliar's figures for Sinornithosaurus, 
> I 
> >found his statement "... the conclusions arrived at by Xu et al. 
> (2001) 
> >are not only seriously flawed and technically unsound but 
> misleading to 
> >the reader both by the extremely poor quality of their figures 
> >(uninformative in vital respects) ..." hilariously ironic.
> 
> Something else that puzzles me about the _Sinornithosaurus_ section 
> is the 
> fact that the "protofeathers" originally depicted in Xu et al. 
> appear to 
> have pigmentation, whereas a lot of the strands illustrated in the 
> current 
> paper don't seem to. Unfortunately, as you point out, the pictures 
> aren't 
> the best, and make it hard to tell what's going on. Some of the 
> strands 
> pointed to may have become separated from the larger tuffs before 
> fossilization.
> 
> [snip]
> 
> >Pelecanimimus is less convincing.  There are supposedly overlapping 
> scales 
> >on the forearm, some with "fingerlike projections".  These are 
> >photographed (though not in relation to any bones), but they don't 
> 
> >immediately strike me as scales.  At least not dinosaur scales.  
> They seem 
> >to be diamond-shaped, like you'd find on a gar.  Maybe 
> Pelecanimimus did 
> >have rhomboid overlapping arm scales.  I can't help but think of 
> >Santanaraptor though (which Feduccia et al. mention as an unnamed 
> >theropod), which the authors describe as having "a thin epidermis, 
> formed 
> >mostly by irregular quadrangles bordered by deep grooves in a 
> criss-cross 
> >pattern."  Amusingly, if the authors are right, this destroys their 
> prior 
> >argument dinosaurs lacked overlapping scales, so couldn't evolve 
> feathers 
> >(under Maderson's outdated developmental scheme).
> 
> The caption for figure 15B states "Skeletal reconstruction of 
> _Pelecanimimus_ (modified from Carroll, 1988)", but _Pelecanimimus_ 
> wasn't 
> described until 1994, and the closest thing I can find in Carroll is 
> an 
> illustration of _Struthiomimus_ (figure 14-9). Is it kosher to label 
> a 
> modified reconstruction as being of one dino when in fact it's of 
> another, 
> or am I being pedantic?
> 
> 
> [snip]
> 
> Regarding _Caudipteryx_, Feduccia et al. state that "According to 
> recent 
> paleontological theory, everything related to the lineage of avian 
> origins 
> must be developing flight from the ground up and all aerodynamic 
> adaptations, regardless of their aerodynamic precision, must have 
> evolved 
> in a context other than flight, as preadaptations. 'Non-avian 
> theropods 
> such as _Velociraptor_, _Compsognathus_, and _Tyrannosaurus_ were 
> clearly 
> terrestrial cursors. Thus, the ancestral mode of life of birds was 
> that of 
> a cursorial biped. Inferences about the habits of _Archaeopteryx_ 
> should be 
> made within this framework and not the inverse" (Chiappe, 1997, p. 
> 110). 
> This line of reasoning completely ignores the obvious bird-like 
> features of 
> _Caudipteryx_, the fact that oviraptosaurs are likely secondarily 
> flightless birds (with _Caudipteryx_ as a basal member), and the 
> fact that 
> it is not parsimonious to assume that the intricate aerodynamically 
> 
> designed detail of the positioning of the remiges of the avian wing 
> evolved 
> in a nonflighted theropod (Fig. 26)."
> 
> The Chiappe paper was published in 1997, and _Caudipteryx_ was 
> described in 
> 1998. Isn't it a bit unfair to criticize Chiappe for ignoring 
> _Caudipteryx_ 
> when it hadn't even been described yet?
> 
> [snip the rest]
> 
> 
> 


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