[Rockhounds] Coprolites

[Tim Fisher]

I and others have talked to Ms. Skinner about the paper. She admits 
that neither of them have been anywhere near Salmon Creek, WA. Once 
again, I find it preposterous that anything, including "guts" of 
vertebrates could be perfectly preserved while the rest of the animal 
left absolutely no trace. I invite her to watch a dog poop the fresh, 
un-eroded concretions found in such abundance at Salmon Creek. Said 
dog would have a very bad feeling in its hindquarters from the almost 
fractal, sharp edges all over the surface of the concretions as they 
are present in the Wilkes clay, before they are weathered by the 
stream. There no concretions that look anything like those in the 
paper present in the un-eroded clay of the Wilkes Formation. All of 
their samples were purchased at rock and mineral shows or online. All 
have been severely weathered by the stream. I liken their paper to 
the blind men describing the elephant. It simply does not hold water 
when confronted with the whole picture at Salmon Creek.

At 04:44 PM 4/8/2008, you wrote:
>At the Tucson show we bought a bunch of 'crorolites' from Madagascar and
>because we had so many customers ask about what they were, I did a bit of
>research on the net and the best thing I found written about them was 'A
>Fresh Look at Sideritic 'Coprolites' by Adolf Seilacher, Cynthia Marshall,
>H. Catherine Skinner and Takanobu Tsuihiji in the Journal of Paleobiology,
>Vol 27, No.1 (Winter 2001) pages 7-13. I even paid $12 to down load the
>article. The authors believe that 'coprolites' are the fosilized remains of
>the intestinal tracts of dead amimals. The authors observe  that fresh
>animal dropings are commonly pointed at one end only and invite any doubters
>to watch a dog deficate. They also point out that the striations observed on
>the 'coprolites' are very much like those one might expect would be fromed
>by the mussel bands observed in the intesteines of many animals. The authors
>conclude:
>
>1. On morphological grounds we claim that twisted sideritic 'coprolites'
>from fluvial deposites of avrious ages are intestinal casts (colonites). In
>the very special microinvironment of the gut, good contents must have become
>mineralized immediately after death- presumably by the bacteria already
>present.
>2. Since no other vertebrate remains are preserved in the beds conaining
>these fossils another diagenic event must have wiped out the phosphatic
>bones and teeth and transformed the premineralized gut contents into
>siderite. Groundwater roll-fronts provide a possible mechanism.
>3. These preliminary findings call for more systematic excavations and
>actuopaleontological, sedimentological and geochemical studies of this
>remarkable taphofacies.
>
>Sideric colonites convey an important general message. It is clear that an
>intestinal cast can form only after death: a rare case indeed compared to
>the thousands of droppings some indifidual has produced during its life
>time, Yet, taphonomy is a scinece of the rare cases, because in geological
>time organismic remains adccumulate not according to orginal numbers, but in
>proportion to their relative fossilization potentials, where the rare event
>may become the common occurrence.'
>
>Rock

Tim Fisher Ore-ROCK-On!
Web Site: http://OreRockOn.com