The more I look at it, the photo in the story below
seem incongruent
with my slowly growing experience of literally
living on top of Hell
Creek outcrops. The mud (with cracks) seems
unnatural on top of the
lichen. Most local lichen (of the type this looks
to be) grows on
sandstone surfaces devoid of any mud. Lichen (of
which individual
colonies may be quite old and very slow growing)
seem to prefer
really long term stable rocks with clean exposed
sunlit surfaces. In
other words, the grain of the surface surrounding
the lichen doesn't
look like a natural occurring surface of Hell Creek
sands. It looks
like wet down scattered mud. The bentonitic muds in
HC wouldn't let
lichen grow on the surface (or rather the lichen
wouldn't grow there
because of the swelling nature of the bentonitic
clays). So what I
am saying is, it looks like a photo of some lichen
with some mud
splattered on top which seems to "enhance" the shape
of a foot
print. I am not saying it is a fraud, just that the
photo doesn't
look convincing to someone who looks at Hell Creek
sand/muds/clays
nearly every day.
In my experience, chunky mud that looks like this
from Hell Creek was
freshly dug from an outcrop and got wet once. The
wetting breaks it
into small irregularly shaped chunks as in the
photo. Mud that has
been weathered on a lot would be very smooth, fine
and a consistent
floury grain size. I would love to see more, higher
resolution
photos of it with a scale showing the surrounding
outcrop.
Everything just seems wrong to me.
Again this is all speculation from an inadequate
photo but the other
thing that it could be is highly weathered bone
(powdered) weathering
out in some odd cross sectional exposure with the
muddy surface.
(Assuming my lichen identification is incorrect.).
I have seen very
similar things (in different shapes of course) from
the root zone
(highly weathered portion) of HC bone beds .
It would also be interesting to know where in the
700 feet thick
sequence of Hell Creek formation, this was located.
Oldest rex
footprint? Hummm. Typical press coverage of
oldest, biggest,
baddest, most, smelliest, etc, etc, etc.
Frank (Rooster) Bliss
MS Biostratigraphy
Weston, Wyoming
www.wyomingdinosaurs.com
On Oct 10, 2007, at 12:00 PM, Denver Fowler wrote:
Beautiful prints only a few mm thick can appear
on the foreshore
at Hanover
Point, Isle of Wight, England only to be washed
away by the next
few tides so
thickness doesn't seem to be important.
Not really. Most of the IOW prints are visible
because they are
infilled with clay or sand of a different colour.
It's not so much
that the print/cast itself is only mm thick: most
of the sst prints
are pretty darned thick, up to a foot or more (!)
and often show 3d
twisting of the foot etc. really cool actually.
The clay prints are
still 6 inches deep or more: about what you'd
expect for a large
animal stepping onto soft mud. These thick prints
get slowly
serially sectioned by the erosion of the tide, and
can look not-
much-like prints once they get a little eroded.
Some iguanodon footcasts: