Page 32 - The Restless Earth Fossils

the tortuous road to Fossilhood 31

water filters through the tree’s muddy tomb, entering pores and
even the empty spaces within individual plant cells, whose walls
are made of relatively tough materials like cellulose and lignin.
As water evaporates, minerals crystallize out of solution. This
process is called permineralization. Replacement occurs when
the carbon compounds making up the tough lignin and cel-
lulose of the wood are later replaced by calcite, iron, or other
mineral compounds.

first dried out and become a natural mummy—perhaps because it
died in some protected place where no predators could reach it—and
then was transported to a final resting place during a flash flood that
quickly buried it. In this final tomb, it was petrified and preserved
for more than 65 million years.

George and Levi Sternberg found this mummified carcass of an
Edmontosaurus dinosaur in Niobrara County, Wyoming in 1908.

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