Here is your short essay on Fossils Shyam Soni Advertisements: The word 'fossil' has been derived from the Latin word 'Fossilium', which literally means anything dug out of the earth'. These are recognisable remains of once-living plants or animals, most of which have been extinct for many thousands of years. They were preserved in sediments, rocks and other materials such as ice, tar, amber etc.
Actually, the fossil refers to organic remains taken from the earth. So in common sense, fossils are the traces of the past life forms in the womb of the earth. These include amino acids, hydrocarbons, fatty acids, lipids, carbohydrates and the derivatives of other organic compounds. The existence of insoluble kerogen is used as proof of biogenicity.
Similarly, the occurrence of pristane and phytane, degradable products of chlorophyll molecule, may be used as proof of photosynthesis. Trace Fossils or Ichnofossils: These include animal tracks or foot print preserved in rocks, burrows of invertebrates, coprolites fossil excretesgastroliths polished stones in the abdomen of dinosaursgnawed bones, etc.
Microfossils are visible only after maceration of sediments. Large parts of plants like leaf, stem, root, flower, seed, etc. These are visible to naked eyes and are the better source of morphological as well as anatomical studies.
Generally, internal structure is not preserved, however, in rare instances cuticles, stomate, etc. Impression may be defined as the negative of a compression. These are just impression of plant parts which do not contain organic matters as in compression Fig.
The sediments containing the flattened plant parts become hardened and when split open shows the negative Fossil essay i. These are the best, but rarest types of fossil which preserve the external form as well as the internal structures.
The petrified fossils can be cut into small pieces and series of section can be made for anatomical studies Fig. The internal structure is degraded to form a cavity which is completely filled up by the surrounding sediments. Thus, the external preserved surface of the plant part is called a mold Fig.
Stigmarian root system is an example of mold, while the pith cast of a Catamites stem is a common example of incrustation Fig. A certain time period is required for the formation of a fossil.
Coal is a compressed fossil, while peat, an early stage of coalification is referred to as sub-fossil. These fake structures are mistaken for plant or animal remains. These are known as pseudofossils. These are results of tectonic movement of earth or other geological upheaval. The petrified spherical balls containing plant parts are commonly termed coal balls Fig.
These spherical balls are formed as a result of infiltration of plant debris in swamps by carbonates of calcium or magnesium, thus restricting the conversion of the debris into coal.
Coal balls occur in localised regions and they range in few centimeters to several meters and weigh from a few to several pounds. Coal balls are specifically significant in palaeobotanical studies.
It consists of thin dead leaves, dispersed in organic matrix. The inner tissues of leaves are destroyed, thus the paper coal consists of layer after layer of cuticles, often with decomposed stems. The carbonaceous lime stone horizon at Tovarkovo, in Toula in Russia, is an example of paper coal.
The fossilised resin of extinct coniferous trees, Pinus succinifera in particular, is called Amber. The resinous exude flowed due to injury caused by boring insects which eventually accumulated on the forest floor and got hardened forming amber. Insects and flowers are often found preserved in amber.
Amber has high economic value and used in jewelllery.
Monograptus is an index fossil of Lower Devonian, while Myrepollenites is a marker of Eocene. Foraminifera, pollen grains, spores etc. The whole plant is not preserved, but only detached plant parts like stem, root, cone, leaf, etc.
These detached plant parts are being discovered in different times by different authors.
Thus, these detached plant parts or organs are given a bionomial generic and specific name by the same set of rules under the International Rules of Botanical Nomenclature which have been framed for living plants.
The first valid description of Lepidodendron came into existence from the publication of Sternberg in Each detached organs or fragments is given a different name.Essay on Fossils: Evolution and Common Descent.
Fossil record is evidence of evolution because of the fossils that scientist have found.
Over the past years scientist found fossils of the same animal but with different features and how it changed over the years. Unlike most editing & proofreading services, we edit for everything: grammar, spelling, punctuation, idea flow, sentence structure, & more.
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- Fossil Fuels Fossil fuels are created from organic material that was created millions of years ago. Petroleum, a fossil fuel gets its name from two words, "petra" meaning rock and "oleum" which means oil. For example, presence of fossil trees or stumps indicates the terrestrial environment and in a similar way the fossils of corals and echinoderms, etc.
are suggestive of marine environment. 4. Fossils also help in ascertaining the palaeoclimate. Free Essay: Fossil Fuels In the world today the environment affects everything. The environment affects what buildings can be built to what the climate will.
School Chemistry essay The Fossil Fuels in Our Life Class INTRODUCTION Fossil fuels are fuels that are formed by natural processes. The process responsible for the formation is mostly anaerobic decomposition of buried dead organisms.