RE: Herbivory widespread in Coelurosauria

[Mickey Mortimer <mickey_mortimer111@msn.com>]

An interesting study, but I note in figure 2 Yanornis is shown as having 
extrinsic evidence of herbivory while Confuciusornis is left with an ambiguous 
entry.  Yet both taxa are known from specimens preserving fish remains, as the 
supplementary information table S1 correctly indicates.  By their rules in 
table S1, Confuciusornis should be marked as having character 8 (evidence of 
carnivory: present only) since it has character 7 (vertebrate gut content: 
present only), which would then make it marked as lacking character 9 
(extrinsic evidence of herbivory).  Similarly, Yanornis should be marked as 
having character 8, which would force 9 to be polymorphic since it also 
preserves direct evidence of herbivory.

There's also more of our friend the incompletely coded matrix.  Looking at 
Confuciusornis and Yanornis for instance since we're already dealing with them, 
neither is coded as lacking a U-shaped symphysis.  Yanornis isn't coded for its 
unserrated premaxillary teeth, densely packed teeth or short ischium.  
Strangely, neither characters 1 nor 3 are coded for any taxon in the matrix.  

Also, Confuciusornis is miscoded as having a decurved anterodorsal dentary 
margin, lacking a ventrally displaced mandibular glenoid and having an ischium 
over 66% of pubic length.  It's also coded as lacking an inset dentary tooth 
row, conical anterior dentary and+or premaxillary teeth, elongate premaxillary 
teeth, unserrated premaxillary teeth, lanceolate cheek teeth, recurved teeth, 
ziphodonty, heterodont dentition, procumbant premaxillary teeth or having 
replacement waves between teeth, but all of these should be inapplicable since 
it lacks teeth.  Yanornis is miscoded as lacking tooth recurvature.

This is out of 31 characters, mind you.  So that's 21 wrong codings out of 62.  
Note too there are unecessary characters such as "dentary exhibits tooth loss", 
when the list already contains "rostral dentary exhibits tooth loss" and 
"caudal dentary exhibits tooth loss."  Also "rostral teeth (premaxillary or 
dentary) conical to subconical" when it contains "premaxillary teeth conical or 
subconical (e.g., “incisiform”)" and "rostralmost dentary teeth conical: absent 
(0), present (1)."

So while I don't doubt the general observation that maniraptoriforms were more 
herbivorous than most other theropods, I'm skeptical of the character 
distributions and statistics.

Mickey Mortimer

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> Date: Mon, 20 Dec 2010 20:59:27 -0700
> From: xrciseguy@q.com
> To: dinosaur@usc.edu
> Subject: Herbivory widespread in Coelurosauria
>
>
> A free .pdf is available at the link:
>
> http://www.pnas.org/content/early/2010/12/10/1011924108.abstract
>
> Guy Leahy
>