Many of us tend to think that the only evidence of a fossil is a bone that was carefully preserved in a rock. The truth is that a fossil can take many forms such as a print, nests, and animal droppings. Fossils are important to science because they are our connection to our distant past.
And since we have the technology to analyze animal and plant fossils, we can learn more about the biology of extinct creatures and plants. The experts who do this job are called paleontologists. They have many methods to study fossils. These methods are what help them determine the age of the fossils and how they would have looked like.
How and Where Are Fossils Formed?There are many ways by which plants and animals turn into fossils. The most usual is through getting buried under sediment once the creature passed away. As time goes by, the sediment hardens enough to become a rock. And because the creature is wrapped around with it, its bones are preserved. There are times when we find shells embedded on rocks.
Sometimes we see foot prints. In some cases, we discover the entire skeleton of either a human being or an animal. Paleontologists have discovered creatures in cave walls, cliffs, and even in ice. This is how mammoths were found. Some of these still have their whiskers and fur.
There were even discoveries of insects that have hardened in the sap of trees. This sap, over time, have turned into hard amber. An amber is a translucent material that looks like a gem stone. Anyone could see through it.
Fossils have been discovered from different places around the world. In the U.S., each state has its own State Fossils.
Examining PrintsWhen a fossil is discovered, the people who found it must be very careful so as not to destroy it. Although fossils are typically found in hard rock, they are still vulnerable to getting damaged by unskilled hands. Scientists used special kinds of tools to extract the fossils from the rock. They use these tools to chip the rocks very slowly. In some cases, they cannot remove the fossil so they just take the entire boulder of rock to their laboratories.
Some fossils are nothing more than a few parts of an animal. It will take time for paleontologists to piece these fossils back together as they need more samples. By analyzing its structure, the scientists will know if this fossil belongs to an animal that has already been found before or if it is a new animal that has never been seen before.
Radiocarbon DatingA scientific method to determine the age of a fossil is radiocarbon dating. All living creatures have a large amount of carbon because we breathe it. However, only a fraction of this carbon is radioactive. When a living creature dies, the carbon intake stops.
If this living creature is fossilized, some carbon gets trapped with it, including radioactive carbon. But like any other radioactive material, it decays over time and it disappears. Paleontologists know how long it takes for a radioactive material to decay.
And because they know the rate of decay, they can calculate how long this radioactive carbon has been around. And they can measure how long the animal has died.
This method works best for fossils that are at least 50,000 years old. Apart from carbon, scientists also test other elements found in them. And because of this, they can study these elements, they can trace the age of a fossil as far back as two billion years!
Now, these techniques are not perfect. The age they determine are educated estimates. This is why we always see the word "circa" when the age of a fossil is labeled. It means that it is not an exact date but just an approximation.
Finding FossilsYou can find fossils yourself. To do this, you must visit your state's office of geology. The government staff will let you know where to find them and what rules you should know.
Additional ResourcesHere are some cool things that you can read about fossils and carbon dating. Try a few activities and make your own fossil crafts!