Fossils – the clue of nature
Fossils are the remains and imprints of plants and animals that lived on Earth in the long past era. But turns into a fossil only a small part of plants and animals. As a rule, their remains are either eaten by other animals or decomposed by the action of fungi and bacteria. Shells or hard bony skeletons persist longer, but eventually they are destroyed. It was only when the remains are buried in the ground very quickly, before they have time to decompose, they have a chance to survive and turn into a fossil. To the deceased plant or animal was buried rapidly, it is necessary that over it there was a sediment, for example sand or silt. Then his remains were soon denied access of air and not rot. Over millions of years of sedimentary layers of the lower pressure of the upper turn into solid rock.
Water that seeps into sedimentary strata, contains minerals. Sometimes she washes them out of the sedimentary material. Under the weight of the upper sedimentary layers of the water displaced from the bottom. Minerals remain within and contribute to the bond of the sedimentary layers and their solidification into rock. These minerals are deposited even in the remains of plants and animals, filling the spaces between their cells, and sometimes even “replacing” their bones or shells. So obratimosti naturally grow in the stone and remain there for millions of years. After a long period of time, the collision of continents can squeeze this rock from the seabed to the surface, and drying is formed. Then rain, wind or the sea will gradually destroy the breed, revealing the hidden fossils. The science that studies fossils is called palaeontology . which translated from Greek means “the study of ancient life”. To recreate the picture of the past using fossils is far from easy. Even in those extremely rare cases when the remains of plants and animals are recorded very quickly sedimentary layers and are preserved as fossils, they generally do not remain undisturbed. Rivers and streams can carry and dump them in the pile by chopping an entire skeleton. While heavier fragments settle and take a different position than in life, while the lighter are washed down with water. Flooding and landslides often break the protective blanket of sedimentary strata, appeared above the fossils. Paleontologists need to be sure that fossilized remains found in a particular place, belong to the animal that actually died in this place and in the same position in which it is found. If this is indeed the case, these findings collectively referred to as the lifetime accumulation . The study of such clusters allows you to identify which animals lived in the area, the nature of their environment (whether they lived in water or on land, whether the climate is warm or cold, wet or dry). The fossil record, which have found their last resting place far from the places where these animals were killed and plants are called post-mortem congestion .
As evidenced by fossils.
Environment – fossils allow us to determine the type of environment in which was formed this rock; the Climate of the fossils can be judged on the nature of the climate of the area in antiquity; Evolution – fossils allow us to trace changes in biological shape over millions of years; the Dating of rocks – fossils help to establish the age of the containing rocks, and to trace the movements of continents.