Re: [dinosaur] I can't see the skull

Ben Creisler
[email protected]



In the case of the Corral Bluffs mammal skulls, it's a freshwater river and
floodplain environment with mudstone and sandstone. The Science paper says:

Most are three-dimensionally preserved in hydroxyapatite concretions and
are found in all observed facies, often as articulated skeletons or skulls
with intact delicate structures such as middle ear and hyoid elements.

===

This free paper from last year fills in details about marine concretions
around organic remains. It's marine, but I assume something similar
happened.


Hidekazu Yoshida, Koshi Yamamoto, Masayo Minami, Nagayoshi Katsuta, Sirono
Sin-ichi & Richard Metcalfe (2018)
Generalized conditions of spherical carbonate concretion formation around
decaying organic matter in early diagenesis.
Scientific Reports 8, Article number: 6308 (2018)
doi:10.1038/s41598-018-24205-5
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On Tue, Oct 29, 2019 at 3:06 PM David Marjanovic <[email protected]>
wrote:

> > What process causes the concretion?
>
> Precipitation of minerals from groundwater in the acidic-or-whatever
> microenvironment created by the decay of soft tissue. (Remember that most
> fossils are fossils of rotting cadavers.) Or maybe just crystal growth on
> the skull itself.
>