text: Fossil Formation |
  Geologic Time |
  Dinosaur Facts |
  Johnson Farm Tracks |
  Swimming Tracks |
  Dinosaur Eggs |
  The Formation of Fossils
  Fossils are the record of life preserved in monuments of stone. Almost all
  living organisms can leave fossils, but usually only the hard parts of plants
  and animals fossilize. Soft internal organs, muscle, and skin rapidly decay
  and are rarely preserved, but the bones and shells of animals are good
  candidates for fossilization. Almost no fossil record exists for soft
  organisms such as jellyfish and worms.
  Dinosaur Track. [ more ] |
  Raptor Dinosaur Egg Fossils. [ more ] |
  Copralite - Dinosaur Dung. [ more ] |
  Dinosaur swimming tracks. [ more ] |
  Fossils include the footprints of animals left in soft mud, later to be buried,
  and turned into stone. In some areas herds of fossilized tracks have been
  found such as at the
  Johnson farm in St. George, Utah. One of the more exotic
  fossils is that of swimming tracks made by animals as they brush
  against the mud and silt floors of an ocean or lake. Under certain
  circumstances fossils of animal dung,
  eggs, and even complete
  nests with eggs
  have been preserved in stone.
  A spider entombed in amber. [ more ] |
  Fossils are formed in a number of different ways, but most are formed when
  a plant or animal dies in a watery environment and is buried in mud and
  silt. Soft tissues quickly decompose leaving the hard bones or shells
  behind. Over time sediment builds over the top and hardens into rock.
  As the encased bones decay, minerals seep in replacing the organic material
  cell by cell in a process called "petrification." Alternatively the bones
  may completely decay leaving a cast of the organism. The void left behind
  may then fill with minerals making a stone replica of the organism.
  Fossils can form in unusual ways. Small bugs or insects can become
  trapped in tree sap. Eventually the sap hardens and forms the semiprecious
  material called amber. In some pieces of amber the entombed remains of
  organisms can be found. Volcanic eruptions can form fossils when animals get
  trapped in the hot ash flows. In this case, the fossil is a hole in the
  shape of the animal.
  By far the most common fossil remains are those of shelled invertebrate sea
  loving creatures such as snails, corrals, and clams. These make up most of
  the fossil record. Plants can leave fossils. In fact coal is the fossil
  record of whole forests; however, individual plant structures usually do not
  survive as the plant materials are compressed to less than one hundredth of
  their original size.
  Fossils of land animals are scarcer than those of plants. In order to become
  fossilized, animals must die in a watery environment and become buried in the
  mud and silt. Because of this requirement most land creatures never get the
  chance to become fossilized unless they die next to a lake or stream. Indeed
  there may be whole species of land animals in which no fossil record has been
  discovered. We may never know how many and diverse these animals were.
  Copyright © 2003-2008 Calvin & Rosanna Hamilton. All rights reserved.