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What Is the Approximate Date of Dinosaur Fossils?

It is only known that dinosaurs existed because their fossilized remains have been found. These remains are either discovered accidentally, usually when some upheaval has brought them to the surface, or by design when teams of interested investigators search by digging in areas where they are likely to be found. One obvious interest is when dinosaurs lived, but accuracy can be problematic.

Relative Age
- One method of determining age is by relative dating. This makes use of the fact that broad time frames can be identified by layers that have built up in rock formations. Inasmuch as a fossil is something that has become embedded in the crust or rock formation of its time period, broad eras when particular dinosaurs lived can be established by examining and identifying the layer of rock in which the fossil is embedded.
Absolute Dating
- This method, also called radiometric dating, uses an approach which is based on the fact that all radioactive elements will decay and reduce in their ability to emit radiation. This process can be measured through various stages and with the assistance of mathematical calculations. Thus, radioactive material in the vicinity of the fossil can be age dated and the fossil assumed to be of a similar vintage. An associated method commonly used with wood and bones is carbon dating. This measures the decreasing radioactivity of carbon found in green plants.
Inaccuracies
- The relative dating method has two potential areas of inaccuracy. The first is that the epochs, or time periods, during which the layers of identifiably different rocks layers formed are long ̵1; lasting millions of years ̵1; so the date is very approximate. The possibility, furthermore, exists, that the fossil may have become misplaced due to some disturbance or upheaval. Absolute dating can be inaccurate because, according to the Radiometric Dating Game, it is based on three arbitrary assumptions, namely that the rate of decay is constant, no elements have been lost and that there is a known amount of initial "daughter" element. A daughter element is an element that results from the decay of a radioactive ̶0;parent̶1; element. The latter remains radioactive whereas the latter is stable. According to West Virginia University, the rate of decay is geometric rather than linear.
Approximate Dates
- There are three distinct geological periods when dinosaurs lived ̵1; the Triassic, the Jurassic and the Cretaceous. The approximately 700 different species that have thus far been discovered via their fossilized remains embraced all three. Different species lived in each of these periods. Dinosaurs are believed to have become extinct about 65 million years ago, during the Cretaceous period, and their earliest remains have been dated to approximately 165 million years earlier ̵1; 230 million years ago ̵1; to the Triassic period.

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