Fossils are an undisputable record of the past. Geologists come to the aid of society in ‘digging the past’ with the help of the study of fossils.
A fossil can be described as an organic object coming from a plant or an animal that was alive at the very time when the rock in which it now lies buried was being actually formed. For a layman it is just an organism turned into stone. The process of fossilization is quite complex.
It is seen that hard parts of an organism get fossilized. The soft parts are decayed.
Preservation of an organism as a fossil requires rapid burial in something that protects the organism from destruction by scavengers, bacteria or weathering. The organisms living in a sea have more chances of fossilization as the aforesaid conditions are better met there. Land dwellers have lesser chance except those buried in lakes, swamps or sometimes floods. Fossils found in volcanic ashes, indicate burial of organisms in the ash spewed by the volcano.
Fossil assemblages many times represent actual death assemblages. In Spiti valley (Lahul and Spiti district, HP) near Lalung village the rocks on the mountain slopes have a fossil assemblage of marine organisms (ammonites) about 250 million year old. It has to be seen to believe the colossal graveyard in the ancient seas. Similarly at Ramnagar situated northeast of Jammu in the Siwalik Hills one finds an admixture of teeth of crocodiles, hippopotamus and rats. Layer after layer that can be extracted with a pen knife. It looks as if a huge swamp became a booby trap for myriads of creatures!
Many times a whole animal is preserved as a fossil with skin, hair and entrails intact. Fossil mammoths of Siberia are an example. It is interesting to know that the teeth of the Siberian mammoths were a source of ivory in Western Europe till World War I in 1913 and fossil ivory worth 57,600 pounds was sold each year at Yakutsk. Fossil eggs are among the rarest of fossils. A clutch of dinosaur eggs have been reported from several places in India as well.
Fossils have multiple uses and help palaeontologists in deciphering the pages of earth’s history.
Fossils are a vital tool for the study of paleo-ecology, i.e. the relationship of past living beings with their environment.
The vicissitudes of past environments were witnessed by organisms now turned fossils. Whole communities of several species were completely devastated due to adverse conditions like severe temperature changes, non-availability of food, volcanic eruptions, severe earthquakes and asteroid impacts etc. Had the temperatures been normal 50,000 mammoths would not have been preserved in Siberia!
Fossils bring to light ancient geography as well. The presence of fossils of marine organisms in the rocks of Mount Everest the highest mountain on the earth and also at several localities of the Himalayas prove that these sky scraper mountains were actually part of the abyss of an ancient sea. The presence of labyrinthodonts, amphibians of geologic past (about 275 million years old) in Kashmir and Madagascar indicate how close the present distant land masses were.
Fossils are a link between the past and the present and a significant tool for the study of evolution. They are the most reliable tool to decipher the age of the strata too.
The preservation of past life as fossils speak volumes about the times to come for the present. Fossil remains amply prove that Mother Nature is a super power. Giant dinosaurs that ruled the earth for millions of years completely vanished. Human beings with a geological antiquity of only thousands of years are trying to over rule Nature. Fossils of the present human race may well be studied by super-humans of the future!
Thursday, October 6, 2005
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