Rock Solid Fossil Facts
By Charles Hopkins
Published 01/2/2008 | Science and Technology
Fossils are remains or imprints providing evidence of the previous
existence of ancient fauna and flora. From a comparatively recent
geologic era of just a few thousand years ago stretching in time to a
period of many hundreds of thousands of years or more in the past is
when fossil formations can be found. They have been discovered
throughout the four corners of the world as infinitesimally small
one-celled organisms to medium-sized mammals to massive dinosaurs
demonstrating the vastly different dimensions fossils can embody.
A fossil holds a very similar form, except that its weight usually
differs immensely from that of the original organism. Plant fossils can
be found in rocks or as petrified wood. Besides fossils in rock, animal
fossils can be teeth, hair, feathers, skeletons, claws and tusks and
even preserved tissue. Insects can be encased in a resin, like amber.
Sea life fossils can be teeth, bones, shells and coral, along of
course, with rock fossils. In addition, the impressions left from the
natural actions of the creature when it was living, such as, paw
prints, tracks and trails can compose fossils. Even bodily functions,
like eggs and stool, are considered part of the fossil record.
Most often the remains of prehistoric organisms are lost due to
predators, scavengers or decomposition. Even so, under proper
environmental circumstances, formation of fossils occurred. Sedimentary
rocks consisting of types like sandstone, shale, coal and limestone are
largely the sort of rocks which fossils can be found preserved inside.
There are several ways that fossils can form. One manner in which
fossils develop is when water penetrates a shell or skeleton building
up minerals inside which over time strengthens the structure. Another
process permitting a fossil to form is when a creature is sealed inside
a material that eventually hardens, like being froze in ice or encased
in a resin. Similarly an animal can be trapped and covered by tar or
volcanic ash. Another type of fossil is the complete drying of the
creature inside and out causing a sort of mummy. Still another method
of fossil formation is under heavy compaction. For instance, an animal
dies and is promptly enshrouded and pressed down by sediment eventually
solidifying to produce a rock fossil. One more fossil type is when the
dead body of an animal has entirely vanished and all that remains is a
hole in the rock just like the shape of the organism. Sometimes this
hole loads up with different materials afterwards.
Besides being interesting and fun to look at, so much can be
learned from the study of fossils. They teach us about the Earth's past
and the ecosystems that prehistoric animals and plants lived in.
Without fossils, we may never have known that certain species had ever
existed at all. Sadly though, they make us aware that there are
probably many fantastic creatures we will never know anything about
since they were not preserved by fossils.