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Re: Not so new papers



David Marjanovich, in response to my post of last night, asked:
 
    "Do you have a figure on that?"
 
    David, I'm unsure what you are asking.  Do you mean a digital image of the Newark Supergroup slab which shows impressions resembling those in Gierlinski's paper?  If so, no; but I could produce one.  Of course, we are not allowed to post such documents to this list, but I could send you, personally, a jpeg of it if you're interested.
 
    David stated as a closing thought:
   
    "The feather impressions from the squatting Condor look indeed like the impressions in question..."
 
    If, in fact, there were 'dino-birds' 205 to 210 million years ago (as is the age of the trace discussed in Gierlinski's paper), it seems hardly reasonable to expect their feather (or, more reasonably 'proto-feather') covering to produce an impression resembling that made by a squatting condor from our age.  In view of the impressions abundantly present on my Newark Supergroup example, which are of identical character to those on AC 1/7, and clearly produced by something other than a couchant dinosaur (and most plausibly make by wind or water-drifting vegetation), and considering the fact that Paul Olsen has examined Ac 1/7 first-hand and with a very experienced eye and completely rejected the feather-impression interpretation (as has Newark Supergroup track expert Donald Baird), it may be best to let a 'dead bird' rest.
 
    Oh, but how delightful it would be to many of us if Gierlinski were right, and Olsen, Baird, and I were wrong.  With that kind of evidential deposit in the contrary 'hypothesis 'bank', even the "Feducciaries" might well be forced to switch investment brokers. :) (Sorry, I couldn't resist.)
 
    But, let's keep on looking cautiously and with cool heads.  Other ichnites could have clearer, more diagnostic stories to tell.
 
    Ray Stanford
 
    "You know my method.  It is founded upon the observance of trifles" -- Sherlock Holmes in THE BOSCOMBE VALLEY MYSTERY
 
   
----- Original Message -----
Sent: Saturday, January 13, 2001 6:01 AM
Subject: Re: Not so new papers

 
David Marjanovic referred to:
 
"Gerard Gierlinski:  Feather-like Impressions in a Theropod Resting Trace from the Lower Jurassic of Massachusetts"...
 
    Several years ago when I first came across this paper, I was thrilled at the thought that a Theropod had left impressions of down or feathers that are preserved from the early Jurassic.  I held this enthusiasm for Gierlinksi's interpretation of the dinosaur body impressions for several years, even after I met Dr. Paul Olsen, probably the world's most experienced researcher on tracks from the Newark Supergroup, in Philadelphia at Dinofest '98.  When I brought up the subject of Gierliski's paper, to Olsen, he told me that he has studied the ichnite carefully and that the shapes interpreted by Gierlinski as probable feather or down impressions definitely are NOT any such thing. He had examined them very carefully and at length.
:.-(
    Frankly, at the time I was a bit taken aback and even slightly offended.  Olsen, I felt, was just too skeptical and most likely wrong.   Being the outspoken person that I am, I flatly told him so!
 
    Within the next year, however, a friend brought some Newark Supergroup dinosaur ichnites to my home.  One of them -- much to my astonishment -- was covered with (all around, and any and everywhere beyond, a theropod footprint) precisely (yes, identical in every characteristic) the kind of traces that Gierlinski interprets as probable feather or down-like imprints.  What is clear, however, is that these are not impressions made by a body covering of any sort.  To my eye, the most probably cause was some type of plant material having been dragged across the wet or damp, very fine-grained substrate by action of shallow water, wind, or both.
Do you have a figure of that?
    Now I have no doubt -- having seen this (and the slab in now in my collection) -- that Paul Olsen's interpretation of Hitchcock's item AC1/7 is the correct one, and Gierlinski's is incorrect.  After all, Olsen -- unlike Gierlinski -- has spent many years (beginning in his youth) studying Newark Supergroup ichnites, and his experienced opinion should carry considerable weight in evaluating Gierlinski's paper.
 
    Of course, I would be delighted to be provided with evidence that both Dr. Olsen and I are wrong, but because of what I have now seen (the Newark Supergroup ichnite now in my collection) it seems well advised to stick with the more conservative interpretation of AC 1/7.
The feather impressions from the squatting condor look indeed like the impressions in question...