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MORE ANSWERS TO TRACK QUESTIONS



Hello, again, Dwight and list,

    Dwight, thanks for a few more interesting questions.  Now, I'll try to
answer them:

-----Original Message-----
From: Stewart, Dwight <Dwight.Stewart@VLSI.com>
To: 'RAY D STANFORD' <STARSONG@prodigy.net>; Stewart, Dwight
<Dwight.Stewart@VLSI.com>; jconrad@lib.drury.edu <jconrad@lib.drury.edu>;
Dino mailing list <dinosaur@usc.edu>
Date: Monday, March 01, 1999 9:22 PM
Subject: RE: thanks for tracks & a question


"...Thanks, Ray.  I figured that HAD to be the case.  The track evidence
for speed
& maneuverability certainly seems to imply active hunting behavior.
BTW: were
there tracks from more than one Dromeosaur at the same site?  What
I'm getting
at here is evidence of pack hunting."

    I've found nothing that would tell me whether the maker(s) of the
Dromeosaur-like tracks were pack hunting, and the few tracks of that type
that I've found were isolated (ex situ) on pieces of substrate that had
evidently been broken out by earth-moving machines (or else by some very
intense flooding).

    The finds of possibly-Dromeosaur tracks are from three widely-separated
sites.  The two most detailed and convincing ones are, in fact, from two
different sites and those two tracks (as I probably mentioned before) show
two feet (one right, one, left) of the very same length, but that's not
large enough a sample to really answer the question of whether this means
the two track-makers  were adults.

    In a third and smaller Dromeo-like track with remarkable depth and nice
splash, it looks as though the 'terrible claw' was lifted very high, whereby
only the sharp tip of it 'met the muck'.  Yet, toes 3 and 4 left impressions
indicating that, in those cases, the flesh, per se, was pressed into the
fine-grained silt with sparse quartz-sand grains that in subsequent
diagenesis has silicified, becoming very dense and hard.  It was the first
possibly-dromeo track I found, and is in a substrate of totally different
nature, compared to the others.

Further, the question was asked, "Those conditions would logically dictate
lower than maximum speeds, which at least leaves open the theoretical
possibility of much faster speeds on more solid ground, right? "


    That seems a very reasonable deduction, Dwight.   I've found some
substantially larger Theropod tracks (definitely not Dromeosaurid types)
that suggest that those particular dinos could run like the proverbial 'bat
out of hell'.  In fact, they remind me of Bob Bakker's and John Ostrom's
early announcements about 'warm blooded' dinosaurs every time I look at
them.  When Bakker spent over six hours with us (looking over the
collection) last year, I could see the "I told 'em so!" delight on his face
when he saw these.

    Dwight, you further said, "AH, Travis County; where my son lives; about
75 miles north of us.  My understanding is that the Mesozoic fossil record
is better in Travis than Bexar County (where I live). Since it was from the
Comanchean, was this sauropod a Titanosaur?"

    Martin Lockley, in his book, TRACKING DINOSAURS (Cambridge University
Press, 1991, ISBN 0-521-42598-0 -- paperback version), states on page 162,
whole paragraph 3, "This means that motorists in cities like...Austin,
Texas, drive over millions of tracks every day as they commute to and from
work above the subsurface tracksite layers."

    Now, as to whether inchospecies Brontopodus birdi's (including my
hatchling tracks' ) maker was a Titanosaurid (or a Brachiosaurid), it may
depend on whom you ask.  In the Dinofest '98 symposium, J.A. Wilson and M.T.
Carrano delivered a very interesting, slide-illustrated paper entitled,
ICHNOLOGY, BIOMECHANICS, AND SYSTEMATICS: GAUGING SAUROPOD LOCOMOTOR
VARIATION FROM THE FOSSIL RECORD.  They presented some very interesting
reasons for thinking that all wide-gauge Sauropod tracks may have been made
by Titanosaurids.  Like the authors' friend Paul Sereno, they waxed somewhat
contra-dogma on some matters, but their ideas appeared to my purely amateur
interpretation, as worthy of serious consideration.  I look forward to
publication of the DINOFEST '98 papers, in order to study in greater depth,
and to evaluate, the possibility that Astrodon (also known by its --
according to Weishampel, Kranz, and others -- junior synonym as
Pleurocoelus) was a Titanosaurid.

    Regards to all,

    Ray Stanford