Paleontology

How are Fossils Formed



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Just as the digital age has made keeping records easier than ever before, fossils are the permanent markers of what plant and animal life was like millions of years ago, long before mankind made his early appearance. Although there are fossils of early man, the most common fossils found yet to date are those of plants and insects. The most "sexy" of the fossils, is, of course, the dinosaur, with a complete skeletal remain bringing in Millions of dollars to the lucky finder or land owner. Even a fossilized footprint of a Tyrannosaurus Rex (T. Rex) can fetch a large sum of money for the lucky fossil hunter, but what exactly made the fossils?

Fossils can be created using six different methods, all of which are very rare in the grand scheme of things. When we stop to consider the number of dinosaurs, plants, insects and other animals that roamed this lovely blue planet, third from the Sun, from 65 to over 250 Million years ago, the number of fossils that have been found to date is awfully small. However, throughout the history of mankind, fossils and dinosaur bones may have been found and used as tools, weapons and other accessories for the fashionable cave man.

The six methods of fossilization are amber, asphalt, carbonization, drying, freezing and permineralization. The most commonly found fossils, and the most common method of making fossils is permineralization, in which minerals fill in the cellular spaces of the plant or animal, and crystallize. The shape of the specimen is preserved as rock, not in rock, often with little to none of the specimen's organic material left behind for more scientific studies.

When fossils are formed by amber, there is a greater chance of organic materials being left behind, possibly even the best chance for cloning dinosaurs, as they often contain blood from dinosaurs or other animals that roamed the planet at the time of the fossilization. Basically, a fly, mosquito or other biting insect is trapped by the sap of a tree or plant, and suffocates as it can not get free. The tree eventually dies, and falls to the ground, and the ground is eventually covered with water. Once the tree, amongst the many others in the region are formed into a coal deposit. The coal deposit is eventually submerged in salt water, until the currents unveil the coal bed. As the amber is let free from the coal, it floats to the surface, since it is lighter than salt water, and is then found along the shoreline of the ancient saltwater body.

Fossils formed by the asphalt method are known for their high quality and quantity, as asphalt is an excellent preserver. One has only to think of the La Brea Tar Pits in Los Angeles to imagine what this scenario looks like. Crude oil seeps through the ground to the surface, and encases any and all plant and animal life, and then the lighter parts of the sticky oil evaporate, leaving behind a thick, sticky asphalt. Asphalt, however, is not common for the elder fossils, like from the eras of the dinosaurs, as this method usually fossilizes plant seeds, animal bones and teeth, and insect shells (exoskeletons), mainly from the Pleistocene era, about 10 to 40 thousand years ago. These fossils are not of great scientific importance, but make for great parks.

Fossils formed with the drying method, or desiccation, in which the animal, human, plant or dinosaur is dried, in an arid geographical area. Soft tissues like skin and fur, organs and smaller bones can be perfectly preserved for thousands of years.

Fossils formed with the freezing method, or refrigeration, is the very best means for preserving ancient tissues, organs, fur and plant matter, and is one of the rarest as well. If the animal or plant is not frozen from the time of death until the moment of discovery, the remains will rot away very quickly when exposed to sunlight and arid temperatures. The way that the animal or plant must be almost "flash-frozen", or instantly frozen, and remain that way until discovered means that only animals that roamed the earth since the last Ice age can be found, meaning that frozen dinosaur fossils can not be found.

The last known method for forming fossils is the carbonization method, or distillation. In carbonization, plant leaves and soft tissue or soft body parts of reptiles, fish and other marine animals decompose, leaving the carbon that was in them behind. This carbon then creates an impression in the outlying rock that surrounds the fossil, and usually provides great detail of the makeup of the plant or animals' body.

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