Transcript Fossil History

Fossils: Pictures of the Past
A tale of discoveries and hoaxes
“Figured Stones”
For centuries, people had noticed images of
plants and animal remains in stones and
wondered at them.
In China, people sometimes found “dragon
bones” (fossils bones of ancient animals)
which were used to make medicine.
“Tongue stones” (fossil shark’s teeth) were
known in Italy as curiosities.
“Fossil”
The term “fossil” in 16th and 17th century
Europe referred to just about anything dug
from the earth: crystals, interesting mineral
concretions, metal ores, and the “figured
stones” that today are called fossils.
Early European theories
The rise of the Enlightenment brought new
ideas about “figured stones”:
Did they grow from seeds or eggs trapped
in rocks?
Were they remains of victims of the Biblical
flood?
Were they organic at all?
Early theorists
Robert Hooke, John Ray, and Leonardo
DaVinci all wrote about fossils, believing
fossils to be the remains of once-living things.
Others, such as Athanasius Kircher (17th
century) attributed fossils such as “tongue
stones” to a “lapidifying virtue through the
whole body of the geocosm.”
Leonardo da Vinci
In addition to his work as
an artist, da Vinci was also
a “philosopher” (scientist),
inventor, and writer.
Several of da Vinci’s
observations on geology
and fossils were
remarkably modern.
(1452-1519)
Horizontal Strata
da Vinci observed horizontal rock strata and
correlated layers on opposite sides of river
valleys in and around the Alps.
He correctly surmised that the layers had
been laid down at the same time and that the
rivers had “sawn” through them.
River deposition
da Vinci observed and recorded that rivers
deposit large, angular rocks near their
sources high in the mountains.
Rocks that are transported by the rivers are
worn down and rounded. Further
downstream, deposited rocks grow smaller
and smaller as the heaver rocks drop out of
slower currents, until at the mouth of a river,
there are only particles of silt, sand, or clay.
Fossils and strata
da Vinci observed clam fossils on
mountaintops in the Alps, and was perhaps
the first to propose that the rocks had once
been sea floor.
He also proposed that where layers bearing
different fossils had been laid down at
different times.
Fossils as organic remains
da Vinci observed that in living clams, the
shells remain closed by a strong muscle,
while in dead clams, the muscle relaxes and
quickly decays, allowing the shells to fall open
and disarticulate.
From this observation, he proposed that clam
fossils with closed shells were the remains of
clams that had been trapped alive in silt.
Steno
(Niels Stensen, 1638-1686)
Danish anatomist,
studied medicine in
the Netherlands and
France.
Came to Florence at
the request of the
Duke of Tuscany to
run a hospital and
continue his
research.
Steno and the Shark
1666: Fishermen in
Livorno, Italy, caught a
giant shark. The local
duke had it shipped to
Steno for study.
Steno noticed
similarities between
the shark’s teeth and
“tongue stones” that
were well known at the
time.
Steno’s leap
Like some others of his time, Steno thought
that shark’s teeth could be organic remains.
However, Steno took it one step further,
saying that the fossils that looked like shark’s
teeth really were shark’s teeth, and were the
remains of once-living sharks.
Corpuscle Theory of Matter
Steno used the Corpuscle Theory of Matter to
explain the transformation of shark’s teeth
into tongue stones.
Naturalists of the day hypothesized that
matter was made of “corpuscles” (essentially
molecules). Steno suggested that the
corpuscles of the teeth had been gradually
replaced by corpuscles of stone as the teeth
sat in the rocks.
But how did they get there?
The obvious question, then, was how did
shark’s teeth end up in rocks on dry land?
Steno’s Principle of Original Horizontality:
Rocks once existed in a fluid state. Rock strata
are formed when particles in a flud such as
water fell to the bottom of the body of water,
leaving horizontal layers. Later disturbances
may alter the horizontality.
Law of Superposition
Steno reasoned that if rocks were deposited
in layers, animal and plant remains could be
trapped in those layers. Later disturbances
could push rock layers above the water’s
surface.
The oldest fossils should be found in the
lowest layers. Younger fossils would be found
in younger layers.
Johann Beringer (d.
1740)
Dr. Johann Bartholomew Adam
Beringer, professor of Medicine
in Würtzburg, lectured widely
on fossils.
Some, he stated, could be the
remains of once-living
organisms. Most, he thought,
were the handiwork of God.
Beringer’s arrogance may have
been the impetus for one of the
best-known fossil hoaxes in
history.
The Figured Stones of Würtzburg
In 1726, Beringer published
Lithographia Wirceburgensis, a
catalog of fossils he and his
assistants had unearthed near
his home.
“God, the founder of Nature,
would fill our minds with His
praises and perfections
radiating from these wondrous
effects, so that, when forgetful
men grow silent, these mute
stones might speak with the
eloquence of their figures.”
The Figured Stones of
Würtzburg
Figured stones?
Some critics who examined the stones were quick to
point out that they bore the marks of a chisel.
Beringer’s response: “...the figures..are so exactly
fitted to the dimensions of the stones, that one would
swear that they are the work of a very meticulous
sculptor... [and] seem to bear unmistakable
indications of the sculptor’s knife... One would swear
that he discerned in many of them the strokes of a
knife gone awry, and superfluous gouges in several
directions.” Beringer believed the “sculptor” was God,
and the stones showed that God was practicing His
skills.
More stones
Some “figured stones” even
bore Hebrew letters, spelling
out the name of God.
Beringer took these as
possible signs that the stones
were the work of the Creator,
but also suggested they could
be sports of nature formed by
the “plastic power of the
earth,” or that some that
resembled living things might
grow from trapped seeds or
eggs.
But whose hand?
Two of Beringer’s detractors, Ignatz Roderick and
Georg von Eckart, admitted to carving and planting the
stones themselves.
Beringer at first accused the men of professional
jealousy, but a public trial revealed that the men had
committed the hoax.
Beringer offered to buy back copies of his book that had
been sold. However, after his death, his publisher
brought out a second edition for the curious and those
with a sense of humor.
Discussion:
Consider the century in which Beringer lived, and
views of fossils at the time. Why was he so quick
to believe the stones were real, and willing to
support a supernatural explanation for the
stones?
In Beringer’s work, he proposed a classification
scheme, asked questions, posed multiple
hypotheses about the origin of the stones, and
invited discussion. In this, how did the quality of
his work compare to that of Steno and da Vinci?