fossils , gabriel costin , gheti teofil

FossilsFossilsCostin GabrielCostin GabrielGheti TeofilGheti Teofil

Universitatea Babes Bolyai Cluj NapocaUniversitatea Babes Bolyai Cluj Napoca

Facultatea de Biologie-GeologieFacultatea de Biologie-Geologie

Sectia Inginerie GeologicaSectia Inginerie Geologica

What is a fossil?What is a fossil?

A fossil is an impression, cast, original material or track of any animal or plant that is preserved in rock after the original organic material is transformed or removed.

A fossil may be:A fossil may be:

• an original skeleton or shell;

• a mold or cast;• material that has

replaced the once living thing;

• traces such as footprints or worm tubes

What conditions promote What conditions promote fossilization?fossilization?

• Hard body parts such as skeletal bones or exoskeletons

What conditions promote What conditions promote fossilization?fossilization?

• Rapid burial and/or lack of oxygen

What are the fossil types?What are the fossil types?

• Body fossils – actual parts of an organism, unaltered or altered

bones, shells, leaf imprints

• Trace fossils – evidence of life that is not a body fossil

tracks, burrows, casts

Body fossilsBody fossils

Trace FossilsTrace Fossils

What are the modes of fossil What are the modes of fossil preservation for body fossils?preservation for body fossils?

Unaltered Original Material - original, unaltered material from the

living organism unaltered bone or

shell

Encrustations or entombments –material is trapped inside coating such as amber


Unaltered Mummification -

quickly dried material

Refrigeration –material is trapped inside ice and tissue is preserved

What are the modes of fossil What are the modes of fossil preservation?preservation?

• AlteredPermineralization –

pores in tissue are filled by minerals

Replacement – replacement of tissue with minerals


• Altered Carbonization –

tissue material is decomposed or reduced to a film of carbon

More on trace fossilsMore on trace fossils

• Mold – reproduction of the inside or outside surface of a living thing

• Cast – duplicate of the original organism; usually formed by replacement of inside of living thing


• Burrows or borings –

Spaces dug out by living things and preserved as is or filled in


• Gastroliths – smooth stones from abdominal cavity of dinosaurs

• Coprolites – fossilized excrement; usually preserved by replacement


• Tracks – impressions of passage of living things