fossils. what are fossils? fossils are the remains of plants or animals that lived a long time ago,...
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What are Fossils?What are Fossils?
Fossils are the remains of plants or Fossils are the remains of plants or animals that lived a long time ago, animals that lived a long time ago, or any evidence of their existence.or any evidence of their existence.
How can Fossils be How can Fossils be Preserved?Preserved?
Unaltered PreservationUnaltered Preservation Altered PreservationAltered Preservation Molds and CastsMolds and Casts Trace FossilsTrace Fossils
Unaltered PreservationUnaltered Preservation
http://web.infoweb.ne.jp/minecity/park/museum/ins_03e.htmlhttp://web.infoweb.ne.jp/minecity/park/museum/ins_03e.html
Insects that got stuck in tree sap were preserved unaltered.
Altered PreservationAltered Preservation
The organism is The organism is preserved but preserved but its original its original skeletal skeletal material is material is altered by altered by chemical chemical changes.changes.
http://www.alertplumbing.com/karls_pics/122500-petrified%20wood.jpghttp://www.alertplumbing.com/karls_pics/122500-petrified%20wood.jpg
Molds and CastsMolds and Casts Molds Molds
A mold forms when something is A mold forms when something is pressed into soft mud and removed by pressed into soft mud and removed by decomposition or pulled out, leaving an decomposition or pulled out, leaving an impression of the object.impression of the object.
Casts Casts A cast is a 3-D representation of A cast is a 3-D representation of
an object from the past. It is an object from the past. It is created when a mold fills up with created when a mold fills up with sediment that hardens.sediment that hardens.
http://www.clas.ufl.edu/users/pciesiel/gly3603c/external.jpghttp://www.clas.ufl.edu/users/pciesiel/gly3603c/external.jpg
Trace FossilsTrace Fossils
http://www.toyen.uio.no/palmus/galleri/montre/x612.jpghttp://www.toyen.uio.no/palmus/galleri/montre/x612.jpg
Trace fossils are Trace fossils are indications that an indications that an organism existed, not organism existed, not the actual organism. the actual organism. They include footprints, They include footprints, nests, tooth marks, nests, tooth marks, worm burrows, root worm burrows, root traces, etc. traces, etc.
Where Where are are
Fossils Fossils Found?Found?
http://necsi.org/projects/evolution/evidence/layers/layers.jpghttp://necsi.org/projects/evolution/evidence/layers/layers.jpg
Why Sedimentary Why Sedimentary Rock?Rock?
http://www.arizonas-vertical-web.com/GrandCanyon/Strata.jpghttp://www.arizonas-vertical-web.com/GrandCanyon/Strata.jpg
NautilusNautilus
http://www.fmarion.edu/~bio106lab/Resources/nautilus.jpghttp://www.fmarion.edu/~bio106lab/Resources/nautilus.jpg
EchinodermsEchinoderms
http://www.ucmp.berkeley.edu/echinodermata/sdollar.gifhttp://www.ucmp.berkeley.edu/echinodermata/sdollar.gif
http://www.viaccess.net/~jacaroe/star.jpghttp://www.viaccess.net/~jacaroe/star.jpg
Chrinoid StemsChrinoid Stems
http://www.nautiloid.net/fossils/crinoids/crinoid4.jpg
http://www.mpm.edu/reef/racine-crinoid-dior.jpg
http://freespace.virgin.net/craven.pendle/fossils/crinoids/stem_oss.htm
Coral FossilsCoral Fossils
http://www.uky.edu/OtherOrgs/KPS/paleoclass/images/bentleycnidaria1.jpghttp://www.uky.edu/OtherOrgs/KPS/paleoclass/images/bentleycnidaria1.jpg
http://tolweb.org/tree/eukaryotes/animals/cnidaria/malu.jpghttp://tolweb.org/tree/eukaryotes/animals/cnidaria/malu.jpg
Fossil MoldsFossil Molds
http://web.ukonline.co.uk/conker/fossils/casts.htm
Sometimes you find a fossil
mold of a shell, like this one. Depending on the shape of
the mold, it is sometimes possible to
make a cast of the shell.
Making a CastMaking a Cast
http://web.ukonline.co.uk/conker/fossils/casts.htm
By filling the mold with plaster, a cast of the fossil can be made. In nature, sediments would fill the mold and
eventually harden, also forming a
cast.