Where are South Africans flying to? August 27, As a travel influencer I fly a lot locally and a fair bit internationally too. Exploring Joburg with new lenses February 20, The voyage of discovery is not in seeking new landscapes but in having new eyes — Marcel Proust Johannesburg, my heart, I love this city so much!
Here is your short essay on Fossils Shyam Soni Advertisements: 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. Nature and mode of preservation: The varieties in the fossils correspond to what is preserved and how it is preserved.
Thus they are of the following nature: Such fossils chiefly include insects preserved in amber, animals in asphalt, and mammoths and other mammals frozen in ice. But such fossils are of rare occurrence and are of recent origin. These are often incomplete and are found in broken fragments.
Conditions favourable for preservation: We know that millions of animals and plants had lived, died and were destroyed without leaving a trace. But it has been observed that two factors are favourable for the preservation of organisms as fossils a The possession of hard parts such as shells and bones, and b Quick burials of the remains by different processes to prevent destruction by scavengers and decay.
Any animal or plant satisfying the above two conditions can be preserved as fossils under normal conditions. The condition hi which fossils occur depends on their original composition and on the material in which they are embedded.
Fossilisation may occur in several ways. Sometimes the soft parts remain unaltered in fossilisation; sometimes only hard parts remain unaltered and sometimes the hard parts are also altered.
In such cases the whole of the organism, including its soft parts is preserved as such. It may be possible due to entombment of the animals under a thick cover of ice. Sometimes insects become entangled in soft and sticky secretions resin of trees On exposure, this hardens and changes to amber and with it the entangled are perfectly preserved.
Shells and internal skeletons are frequently preserved for long periods of time. Many of the best of these are fossils of marine animals that fell into the soft sediment on the sea-floor when they died. Of the land dwellers, those that live near swamps, lakes or sea are most likely to be preserved.
Corals, mollusca and protozoans are examples of this category. In this case, the actual remains of an organism are likely to undergo changes through time. These changes are fostered by the slowly circulating ground waters that carry elements in solution.
It includes the following processes: It is a slow process which involves removal in solution, of each individual molecule; of the material constituting the hard parts and simultaneous precipitation of an equivalent quantity of the replacing mineral.
This molecule by molecule replacement of one substance by another helps in preserving even the most delicate organic structures, as such. In this manner the bones, shells or plant tissues are transformed into calcite, silica or pyrite and the processes are known as calcification, solidification and pyritization respectively.
In this process, the organism is decomposed and it loses nitrogen, oxygen and other volatile constituents.
As a result, it is enriched in carbon and is said to have been carbonised. Coal seams are the carbonised remains of plants. Sometimes, the hard parts preserved within the accumulating sediments, may be totally removed in solution.
As a result, hollows are left within the rock beds which are called moulds.
Porous and permeable rock-beds are able to have seepage of sub-surface water which can remove in solution the shells of organisms, thus facilitate the formation of moulds.
Plants and animals devoid of hard parts, do sometimes leave a record of their existence, in the form of imprints within the rock beds. Impression of leaves, feathers of extinct birds are the examples.
Even though they do not form any part of the animal, yet they are regarded as fossils.From skeletons to teeth, early human fossils have been found of more than 6, individuals.
With the rapid pace of new discoveries every year, this impressive sample means that even though some early human species are only represented by one or a few fossils, others are represented by thousands of.
Here is your short essay on Fossils or animals of the past geologic ages preserved in the rocks of the earth's crust by natural processes are known as 'fossils'. Nature and mode of preservation: The varieties in the fossils correspond to what is preserved and how it is preserved. Thus they are of the following nature.
Fossils in Kenya Essay. 0. Free Essays.
Kenya lies in a strategic topographic point in Africa. Its capital metropolis is Nairobi with a current entire population of 11 million it has an country of square stat mis. Two chief finds in Kenya have made a great part to the development tree. Fossils in Kenya Kenya lies in a strategic place in Africa.
Its capital city is Nairobi with a current total population of 11 million it has an area of , square miles. The fossils were mostly found in Kanapoi Kenya in Anamensis is thought to have existed between and million years ago.
The teeth and jaws are very similar to those of older fossil apes.4/4(1). A time line from before writing began to the present, linked to Andrew Roberts' book Social Science History and to other resources.