Page 24 - The Restless Earth Fossils

the tortuous road to Fossilhood 23

E-Worlds like Colorado, where Johnson lives, wind and water
expose fossils through erosion. Rivers rush down mountains,
carving channels that expose rock that was once mud in some
D-World long ago. D-Worlds, then, are low places like swamps
and ocean beds where the sediments scoured from E-Worlds
pile up and sometimes bury living things. Deposition rules in
D-Worlds. To hide from the recycling powers of nature—such as
wind, water, scavengers, and decomposers like bacteria—a living
thing must enjoy a quick and long-undisturbed burial after it dies
in a D-World in order to become a fossil.
Obviously, a lot of things get buried quickly and never become
fossils. Countless worms live and die in the mud, yet almost none
of these creatures fossilize because they do not have hard parts—
things like bones, horns, shells, and teeth. Soft tissues of plants
and animals can absorb or be replaced by minerals to become the
“formed stones” that have so long intrigued people, but fossils are
not always hard and mineralized. A fossil consists of the remains
or traces left behind by a living creature. Some remains get pre-
served for a very long time with little alteration.

MuMMies, “sapsicles,” and tar pit divers
In September 1991, hikers found the head and shoulders of a man
melting out of a glacier high in the Alps on Italy’s border with
Austria. Five other bodies had been found that year to join six that
were discovered between 1952 and 1990. Most of these corpses
belonged to hikers or skiers who had made bad decisions or were
surprised by a sudden storm. Most of them had died within the
past few years or decades. But the so-called “Iceman,” found in
1991, had met his end on some spring or summer day 5,300
years before. The ice preserved his clothes, tools, the pollen from
hornbeam blossoms that floated in the air around him, and even
traces of his last meal.
High mountain glaciers, like the one where the “Iceman”
was found, act like refrigerators to preserve the remains of living
things. Low temperatures keep bacteria and other decomposers

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