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MODERN
"FOSSILS"?
There has been a increasing
trend in the fossil business to offer impressive,
but
NOT TRUE PREHISTORIC FOSSILS,
of various species of mammals such as bear, bobcat, coyote, beaver, raccoon,
mink, muskrat and wolf, etc.. as being FOSSILS. These are usually
found in river banks or springs and appear to look prehistoric.
They are ANCIENT (less than
10,000 years but maybe only 200 years), but NOT TRUE FOSSILS that date back
over 10,000 years. They
are sold both loose and in artificially created matrix reconstructed to
appear as though the skull is still partially embedded. Dealers will
casually put in the time period PLEISTOCENE - HOLOCENE to keep them
technically off the hook but often the sales descriptions or comments by the
seller will refer to these present-day skulls as "Pleistocene fossils" when
all indications of their characteristics indicate otherwise. For the
prices they are selling for quite frankly, you could buy an old skull from
an animal trapper for considerably less. Both will be "Holocene"!
They look
great but it's simply important to know that THEY ARE NOT TRUE FOSSILS,
that is, they do NOT come from prehistory dating back to a period exceeding
10,000 years ago.
You are buying
an ANTIQUE AT BEST,
not a FOSSIL
WHAT IS A FOSSIL?
Science defines that
a fossil is a preserved
life-form specifically from a
PAST
GEOLOGIC AGE.
Referring to the geologic time scale, we are currently in the HOLOCENE
PERIOD. The term FOSSIL or PREHISTORIC pertains to remains from a
period EARLIER
than the Holocene. The last period considered PREHISTORY or
fossil-bearing, is the PLEISTOCENE PERIOD. This ended 10,000 years ago
and is the cut-off point for what is and what isn't a true fossil. Any
remains of plants or animals AFTER 10,000 years that are found in the
Holocene are NOT
true fossils and should not be presented as such.
HOW CAN YOU TELL?
When you
do not have access to the exact strata that a specimen of a modern species
comes from, it requires some detective work to determine just how old the
remains are. If we were standing in a quarry and look up in the wall
and see a skull sticking out, we may easily be able to determine its age
based on the strata, or layer from which it is buried in. If it is an
extinct species, then we know when the species died and can fairly
accurately date its most minimum age. River terraces can be
problematic to date between a matter of a few thousand years because the
river will always have a history of flooding and receding, thereby jumbling
animal remains in deposits that are not necessarily perfect chronological
layers. Again, this is mainly when we are talking in terms of
thousands NOT tens or hundreds of thousands! of years. These skulls we
are discussing are mainly from river terrace deposits.
It is tricky to date a fossil
on appearance alone but since we know the type of deposit these so-called
"fossils" are coming from, we can apply some common sense deductions to
determine that some features just don't make sense if they were over
10,000 years. Some obvious characteristics that these skulls cannot
be 10,000 years or older are their mere completeness and degree of
intactness which is too good to be true for such age IN THIS KIND OF DEPOSIT,
in the numbers of specimens that are found. Gravel bed, river terrace
deposits dating to the last Ice Age have been subjected to extreme pressure,
movement and disturbances that have no equal after the glaciers receded.
While many nice fossils can be found in such deposits that date back to
prehistoric periods, the energy exerted on the strata often would damage or
destroy the delicate intact skulls of small mammals. Delicate
anatomical features would be eroded, broken or otherwise damaged for a true
Pleistocene gravel bed or river deposit. The skulls being sold in
question, do not show this characteristic damage.
Another feature to make note
is the color of the teeth in relation to the bone. Despite the bone
being stained dark from river tannins, the teeth enamel still retain their
modern natural white hue with no mottling or coloring from the elements.
Note, modern living beaver have orange incisors when they are alive so the
color of these teeth will always look prehistoric, regardless of age.
Over 10,000 year true fossils of white teeth in dark bone also exist in
nature but the teeth will always have some mottling, veining or unnatural
color highlights (blue, orange, red, yellow, etc..) compared to dingy,
present-day animal teeth. Modern teeth from animals can look
discolored but the discoloration will look more like plain old "dirty" teeth
rather than the beautiful colors some true fossil teeth come in when white
is the dominant color.
"BUT IT'S MINERALIZED, HOW COME IT'S NOT A FOSSIL?"
The fact that a bone becomes
mineralized or stained dark is very deceiving when figuring age. In
peat bogs or river and spring deposits, a modern day animal can fall into
the water and, depending on the chemistry of the sediment and water, its
skeleton become mineralized in a matter of just a few hundred years.
Dark river waters that are rich in tannins (tea-colored water caused by
decaying vegetation) can stain modern bone to a color that resembles a
fossil bone from 5 million years ago! Of course, if you want to be
absolutely sure of the age of a mammal skull that looks too good to be a
true fossil, C-14 dating is the least expensive way to determine its age.
Consult your local museum or university as they will often perform this test
for a fee.
OUTRIGHT FAKE FOSSIL SKULLS
While on the subject, it is
worthy to make mention of outright fake fossil skulls we have seen surface
from time to time in the market. Occasionally, outright fakes of
fossil skulls are made by taking a modern animal skull and treating with
stain to appear prehistoric. This article is intended to address
differences between genuine Holocene and Pleistocene remains but the traits
to watch for to identify an artificially created fake fossil skull apply
equally to identifying a Holocene skull. |