How Fossils Are Formed
How are fossils formed ?
Fossils stole my heart -
The fossil record shows that life began in the seas approximately 3.8 billion years ago. Primitive
calcareous sponges built the first reefs, which were home to numerous arthropods, chiefly
Fossils are the remains of past life that have been entombed by geological processes in rock
strata. Life can be preserved in many ways, and fossils vary from vague traces of past activity (
such as footprints). It requires the rapid covering of an organism’s remains by sediment, deep
burial compression and chemical changes involved in rock formation. The fossil record shows
that life began in the seas approximately 3.8 billion years ago.
Fossil sites are very rare and special conditions are needed to preserve high quality fossils,
particularly the soft bodied forms, but over life’s 3500 million year span these rare conditions
have occured in a number of places. They are common in fine grained sediments that occur in
low energy environments such as lakes, seafloors, swamps and the quiet parts of the deltas.
How are Fossils formed ?
Fossils form when an organism is buried and the hard parts of its body, such as the bones,
teeth, nails, shell or woody tissue are preserved either as original material or as an imprint. They
can range from pollen grains to the skeletons of giant dinosaurs or whales. Encapsulated bodies
such as insects caught in amber. Oftentimes, the original material is dissolved away, leaving a
cavity in the rock which may later become filled with another material, such as a mineral.
Limestone, chert, mudstone, shale and siltstone are some of the rocks where fossils can be
found. Mistakew Point, Canada and in the Ediacara Hills, Australia, bizarre precambrian soft
bodied marine life forms, the oldest yet discovered, have stirred much speculation about early
To release them with a hammer and chisel splits them apart along their bedding planes. By
studying the processes of burial and fossilization, scientists have been able to identify rarer
specimens and are always on the lookout for new undiscovered species.