|
The article Gav Rymill (See his posting reproduced below.)
wonders about is as follows:
Feather-Like Impressions in a Theropod
Resting Trace from the lower Jurassic of Massachusetts, by Gerard Gierlinski,
published in The Continental Jurassic, Michael Morales, Editor, 1996, Museum of
Northern Arizona Bulletin 60.
And, yes, there has been much discussion of
this on this list, some of it recent.
In short, Paul Olsen, possibly the most
experienced expert on tracks and other ichnites of the Newark Super Group, has
studied these traces from the Lily Pond Quarry in Massachusetts (Portland
Formation, Lower Jurassic) first-hand and in depth. (Amherst College,
Massachusetts item catalogued as AC 1/7) He is convinced (personal conversation,
1998) that the traces Gierlinski interprets as possible feather impressions have
a much less spectacular explanation.
I have a sizeable piece of Newark Super
Group substrate with a dinosaur track and with impressions that seem identical
to those in the specimen Gierlinski and Olsen have discussed, and those on my
sample seem to have been made by some type of vegetation adrift in shallow water
and brushing against the very fine-grained bottom sediment.
Personally, I would be delighted if AC 1/7
should contain theropod feather impressions -- and, in fact, believed them to be
such on initial exposure to Gierlinski's paper -- but I am now 100% certain his
interpretation is not tenable.
I hope this helps,
Ray Stanford
|