Types of fossils and uses

Fossil types and uses

1. TYPES OF FOSSILS and USES Under the guidelines of Prof. P Madesh. By Hemanth kumar N and Jeffri. J DoS in Earth Science, Manasagangothri .

2. Fossil. Fossil, remains or imprints of plants or animals preserved from prehistoric times by the operation of natural conditions. Fossils are found in sedimentary rock, asphalt deposits, and coal and sometimes in amber and certain other materials. The scientific study of fossils is  paleontology . 

3. Types of Fossil. Fossils have broadly classified in to three types on the basis of their formation. Actual remains Imprints Petrification

4. Actual remains Bones teeth Shells Amber F rozen in ice. In this type the remains of soft and hard parts of the organism won’t alter.

5. Imprints Molds or Casts in mud, sand and etc… that turn to rock. Imprint fossils are formed from an organism moving in some way, leaving behind a trace or track. These tracks are preserved when the clay/silt dries slowly and is covered by other sediment. Plants can also leave imprint fossils when they are covered by sediment. The leaf tissue degrades, leaving an imprint of where the leaf once was.

6. Petrification. Petrified fossils result from per mineralization, the replacement of once-living matter by minerals. Solutions containing silicates, carbonates, iron or other minerals seep into the gaps and spaces between the cells, first encasing the cells and eventually replacing the cells themselves. Over time, minerals entirely replace the organic material, creating a petrified fossil.

7. On the basis of the fossils distribution, occurrence and by their characteristics the fossils have divided into different types. Body fossils: Well preserved entire organism unaltered and altered hard parts and naturally formed moulds and casts are classed has body fossils.

8. Chemical fossils . Well preserved palaeoproteins and amino acids and structures resulting from recrystallization and carbonization process are grouped as chemical fossils.

9. Trace fossils: Footprints, trails, burrows and tubes, coprolites and fossilized eggs are termed as trace fossils and they also known as Ichnofossils.

10. Derived fossils: Fossils whose original home was in some older bed and whose worn and rounded surface, and perhaps different means of preservation or content of matrix distinguishes them from the contemporaneous fossils with which they may be mixed are termed as derived fossils or Reworked fossils.

11. Living fossils: Fossils which range from ancient time upto the present day without any change in their primitive characters are known as living fossils.

12. Remaine fossils: Organic materials which have been rolled and abraded, accumulating over a considerable period before their deposition are termed as Remaine fossils.

13. Facies fossils: Dissimilar assemblage of fossils which are controlled by environment and restricted to certain sedimentary environment are known as facies fossils.

14. Pseudo fossils: Certain structures of sedimentary or tectonic origin which resembles fossilized organic remains are termed as Pseudo fossils. ( dendrite made by a mineral)

15. Uses of fossils: Study of chronostratigraphy: It is concern with the age of strata and their time relation. Biostratigraphy: The fossils contents of beds are used in interpreting the historical sequence. Index fossil and correlation of rocks: Certain animal or plant remains are so characteristics of certain geological origin that they are called as index fossils. They used in correlating in other areas.

16. Study of paleogeography: The adaptation of organisms are characteristics of particular environment hence those shown by fossil forms may indicate the extent and boundaries of formers land, water deltas, mountains, deserts, lake, rivers, shorelines and the position of deep and shallow seas. Study of palaeoclimate: The variation of temperature and the degree of moisture is perhaps most clearly indicate by fossil plant and animals. Study of paleoecology: The study of ancient organisms in relation to their total physical, chemical and biological environment.

17. Study of organic evolution: No line of evidence more forcefully and clearly supports the fundamental postulate of evolution descent with accumulative modifications. Use of fossils in the discovery of new deposits of coal and petroleum. Important coal deposits are normally associated with sedimentary bed containing plant fossils deposited in lake basin during the upper Paleozoic times in India south America south Africa Madagascar and Australia. Study of paleogeophysic: Fossils play an important role in the study of paleogeophysics they can be used to determine spatial relationship of the earth and the moon, the length of days and years, earths force of gravity and paleotides or ancient tidal force during the past.

18. Study of paleoneurology; Under a very resent branch paleoneurology the study of endocranium of the fossil fauna is done basing research on natural or artificial endocranial moulds. Micro fossils: Microfossils data can be used in the study of palaeo currents of sea.  The presence of microfossils in shallow water sediments which lived in deep water, Indicates a global change in the sea level .  The study of microfossils has been helpful in the evaluation of the conditions in which petroleum deposits have been formed. The study of microfossils is very important for petroleum prospecting. Certain characters of microfossils like color, outer shell composition etc. gives an idea about type of petroleum deposition present.

19. Conclusion. Study of fossils have been given a data about the past life on the earth surface. By studying the these fossils will help in understanding the evolutionary trends in life. The fossil studies gives the key to the past environment.

20. References palaeontology, evolution and distribution by….P.C.JAIN and M.S.ANANTHRAMAN. Microfossils by Dr. K. Kathal. Internet resource https://sciencing.com/five-different-types-fossils-7152282.html Slide share. Wikipedia.