Mr suren N Kamble
M.Sc. Geology (SET)
P.G. Department of Geology
Deogiri College, Aurangabad.
2. (Palaios- Ancient, ontos-life, Logy-Study)
(Palaeontology was proposed by the de Blanville & don Waldhelm in1834)
Fossil - Remains or traces of a once-living organism.
“Fossil” (Latin prefix “Fodere” refers to digging/excavation) in its most general sense refers to
any preserved evidence of ancient biological organisms in the rock record that is obtained
through digging/extraction from the host rock.
5. Importance of Fossils
To Study the Biostratigraphy (age dating of rocks)
To Study the Evolution, Geographical Distribution of ancient animals
To Study the Paleoecology/paleoenvironmental interpretation
To Study the Paleogeography/paleobiogeography/Palaeotemperature
6. Modes of Preservation of Fossils
Entire Body Preservation With soft parts
Entire Skeleton Preservation Without soft parts
Petrification & Replacement
Mold & Cast
Traces & Trails
Encrustation in Spelaean Environments
7. Entire Body Preservation
This is very rare mode of preservation of fossil
In this mode the entire body of the animal is
preserved with the skin in extremely dry and cold
The fossil Woolly Mammoth from the Siberia
(1779) found to be entire skin and hard body part.
Amber is a natural tree resin that had hardened
through various chemical changes, sometimes this
sap surrounds an insect, preserve it with perfect
details & look like stone
8. World’s oldest baby snake found preserved in amber
100-million-year-old baby snake preserved inside a
piece of amber from Myanmar.
The new species—dubbed Xiaophis myanmarensis—lived
in the mid-Cretaceous period
The fossil, which was just 5 centimeters in length
9. Entire Skeleton Preservation
This is also an rare mode of preservation of fossil
In this mode the entire Skeleton of the animal is
For preservation of this type fossils the climatic
condition should be extremely Dry or extremely Cold
A new species of South American fossil terror bird
called Llallawavis scagliai ("Scaglia's Magnificent
Bird“) more than 90% of the skeleton exquisitely
preserved (Cenozoic Age)
10. Petrification & Replacement
(The petrification is process of removal of particles of
original animal body parts and replace by the fine grain
sediments or minerals and totally convert it into stone or
When Organism die 'buried it tissue may be replaced by
silica calcite or pyrite or some other minerals through
In short it’s the type of preservation in which alteration
of hard part by Mineral matter or Sediments
Arizona National Wood Fossil Park
12. Mold & Cast
When remains are buried, they are surrounded with
sediment. The impression that the buried object made in
the surrounding sediment is called an external mold.
(impression of shell exterior surface)
If the buried object is hollow, it can also be infilled with
sediment. The impression of the interior of the buried
object is called an internal mold (also known as a
“steinkern”).(impression of shell interior surface)
In many cases, the actual buried object (in this case a shell)
decays or is dissolved, leaving only internal and external
These fossilized Australian Glossopteris leaves are the same ones found on
These imprints basically we get in the very fine
grain sedimentary rock i.e. Shale
The leaf is sandwich between the two strata,
after the decomposition of the strata only the
replica of the glossopteris leaf remains
16. A trace fossil, also ichnofossil.
It is a fossil record of biological activity but not the preserved remains of the plant or animal itself.
The study of such trace fossils is ichnology and is the work of ichnologists.
Trace fossils are generally difficult or impossible to assign to a specific maker. At the highest level of
the classification, five behavioural modes are recognized
1. Domichnia - dwelling structures reflecting the life position of the organism that created it.
2. Fodinichnia - three-dimensional structures left by animals which eat their way through sediment,
such as deposit feeders;
3. Pascichnia - feeding traces left by grazers on the surface of a soft sediment or a mineral substrate;
4. Cubichnia - resting traces, in the form of an impression left by an organism on a soft sediment;
5. Repichnia - surface traces of creeping and crawling.
Ichnofossils- Traces & Trails
18. P.C. uses the relationship of the trace with the
sedimentary surface. According to this traces can be
A. exogenic (on the sediment surface)
or endogenic (within the sediment itself).
B.Traces can be found in full relief (with the boundaries
of circular burrows clearly defined within the enclosing
C. semirelief, either on the upper surface (epirelief),
D. on the lower surface (hyporelief) of a sedimentary