After the death of the animal begins the process of decomposition. Vultures and crows tear at the rotting flesh and entrails, flies and bacteria clear what’s left. The bones disintegrated in the sun and in the rain. So the once living being is nothing.
Sometimes, however, the remains can go to a place where they have a chance to be saved from destruction: to get into the river during the flood and quickly buried in the sand. In this case, the vultures won’t find them, and flies and bacteria won’t have access to the remains to destroy. Such cases are extremely rare — probably only one man for a few hundred years, managed to avoid decomposition. But this happens, and then the body gets a chance to become a fossil. The transformation into a fossil, fossilization, occurs in several different ways. In very rare, special cases, the body of the animal can be maintained with no change. We learned this by watching mammoths buried in frozen silt in the glacial period, and insects, drowned in the resin that oozed from ancient pine trees. These insects are preserved when the resin
turned into a land in amber. Dinosaurs could not harden in this way, because they were extinct long before the ice age and could not climb trees.
In other unique cases, only parts of creatures can survive, but they survived without any obosobi changes. The bones of the ice age mammals have been found in natural asphalt lakes-traps in Los Angeles, USA. But shark teeth are often found in tertiary marine sediments. Preserved in this way remains relatively young in geological terms, but this ability to survive is again incredible for dinosaurs.
Even in cases where animal or plant quickly petrify and stored, geological changes in rocks can destroy the original lifetime of the substance. However, in the dust becomes not all. The leaves and branches of ferns are sometimes retained as a thin black film of pure carbon while all other chemical substances and compounds have been washed from the rock. Plants, of course, can be stored in this way, but. not dinosaurs.
Sometimes, when a bone is buried in sedimentary rocks, the water seeping through the rock, lays the minerals in the bone. She may break down, molecule by molecule, but at the same time a substitution of the bones of the new material, molecule by molecule. The result is a fossilized bone that has the same microscopic structure but consists entirely of new substances, such as silica. It is through this type of fossilization (method of preservation) and were able to survive the remains of dinosaurs.
Bones in sedimentary rocks can then be destroyed so that the stone remains from the bone cavity. Later, ground water, percolating through the rock, fill the cavity minerals (one of them is calcite) and create education, precisely in re-trusted form bone. On such a fossil is called a mold or outer core. On this cast we will not see the internal structure of the bone. The remains of dinosaurs are often found in the form of cavities in the rock and plaster casts.
Do not think that the fossil record is the remains of the bodies or skeletons of animals. Fossil footprints are formed when animals dig burrows in the sand, crawling along the beach. After sand will turn into rock — Sandstone, tunnels and burrows may be preserved in the form of rock structures. Dinosaur footprints is one of the examples of fossil remains of life.
Although some dinosaur bones and can be in the form of fossils, it is rare to find complete skeletons in which all the bones were joined together. Usually a dead animal or itself disintegrates very rapidly, and rastalkivaya or torn to pieces animals-eaters of carrion. Bones, and this is the most solid and durable parts of the body have a chance to be wowed by water at the flood and then suharnitsa in precipitation. Complete skeletons of extinct animals found only in cases, when the corpse was covered with sediment immediately after the death of the animal.
Geologists distinguish two fundamentally different types of fossils occurring together. The first type of post-mortem accumulation of disjointed bones, mixed with fragments of shells and remains of other animals, brought here by water from any other places. The second type reflects in vivo the relationship between organisms, usually nearly complete skeletons,
are found together with fragments of other animals that lived in the same area, and the remains of plants that remained in the same position in which they grew up. The second type gives the geologists a lot more information because they will learn a lot about the lifestyle of studying extinct creatures.
Sometimes, though rarely, fossils testify to the dramatic events in the life of the animal. Fossil bones can be fractured or to have typical scratches from teeth enormous carnivorous animals, and the broken teeth of a predator find nearby. These findings prove that the victim was attacked by some formidable enemies. Sometimes in very well-preserved skeleton can be found in “cavity” of the stomach the remnants of the last dinner, and then we learn about the diet of extinct animal. It happens that two different animals are conserved, clutching at his each other, clutching at the enemy tooth and nail, is the result of a deadly fight that killed them both.