Re: EVOLUTION OF BIRD

["Jerry D. Harris" <102354.2222@compuserve.com>]

Message text written by INTERNET:smithjb@sas.upenn.edu

>>It may be parsimonious out west, but it is not necessarilly that 
way here in the east.  The Newark Supergroup has not produced much in the 
way of theropods, and has never produced a single theropod pedal element 
to my knowledge.  Even in the prosauropods we get from the Newark, there 
is a distinct lack of pedal data.  Most of the work that I have done, 
with Jim Farlow and Paul Olsen, on this subject, by necessity used pedal 
data from outside of the Newark Supergroup because they are simply absent 
from within.  This work seems to suggest theropod trackmakers for most 
of the ichnotaxa examined more strongly than non-theropods, but strongly 
enough for me to want to base anything on it.  The work is still in 
progress in many respects, and I would have to say inconclusive.  And 
almost nothing has been done in the Newark on anything that someone might 
want to call avian.<<

        Josh is, of course, correct...I should've been a bit clearer with
my wording (apologies for any confusion).  All I meant was that since we
_do_ know that Late Triassic and Early Jurassic theropods existed (at that
time, if not in the specific formations in question), but do not know of
any avian or non-theropod, avian-like foot fossils (again, from any
formation, anywhere), the attribution of the prints to the Theropoda is
parsimonious.  Of course, new body fossil data could easily change this! 
8-D

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                     Jerry D. Harris
                 Fossil Preparation Lab
          New Mexico Museum of Natural History
                   1801 Mountain Rd NW
               Albuquerque  NM  87104-1375
                 Phone:  (505) 899-2809
                  Fax:  (505) 841-2866
               102354.2222@compuserve.com