Paleontology or study of fossils is the branch of biology that studies the forms of life that existed in former geologic periods, primarily by studying fossils. The only direct way we have of learning about dinosaurs is by studying fossils. Fossils are the remains of ancient animals and plants, the traces or impressions of living things from past geologic ages, or the traces of their activities. Fossils have been found on every continent on Earth. The word fossil comes from the Latin word fossilis, which means, "dug up". Most fossils are excavated from sedimentary rock layers (Sedimentary rock is rock that has formed from sediment, like sand, mud, and small pieces of rock). Over long periods of time, these small pieces of debris are compressed (squeezed) and are buried under more and more layers of sediment that piles up on top of it. Eventually, they are compressed into sedimentary rock. The fossil of a bone doesn't have any bone in it! A fossilized object has the same shape as the original object, but is chemically more like a rock.

How are fossils formed?

Fossils were formed when some animals were quickly buried after their death (by sinking in mud, being buried in a sandstorm, etc). Over time more and more sediment covered the remains. The parts of the animals that didn't rot (usually the harder parts like bones and teeth) were encased in the newly formed sediment. In the right circumstances (when there is no scavengers, quick burial, not much weathering) parts of the animal turned into fossils over time. After a long time the chemicals in the buried animals bodies underwent a series of changes. As the bone slowly decayed, water infused with minerals seeped into the bone and replaced the chemicals in the bone with rock-like minerals. The process of fossilization involves the dissolving and replacement of the original minerals in the object with other minerals (and or per mineralization - the filling up of spaces in fossils with minerals, and /or recrystallization in which a mineral changes its form). In the end we get a heavy, rock-like copy of the original object - a fossil.

Fossils can also form from what is called Petrifaction.

Petrifaction can preserve hard and soft parts and slowly replaces organic material with silica, calcite or pyrite, forming a rock-like fossil. Wood is often found petrified. Some organisms are embedded in Amber (a hardened form of tree sap). This usually preserved insects or pieces of plants. Fossils of imprints may form, like casts of dinosaur footprints. The impressions, in the right circumstances, fill with sediments that fossilize. Most animals did not fossilize, they simply decayed and were lost from the fossil record. Paleontologist's estimate that only a small percentage of the dinosaurs that ever lived have been or will be found as fossils.

Here are some fossil facts:

Earth's Oldest Fossils

The evidence of microscopic life forms has been detected as old as 3,700 to 3,800 million years ago. This evidence was found in Isua greenstone in Greenland. There have been claims of evidence dating back as far as 3,850 million years ago but these are not universally accepted. Scientists continue to refine dating methods to get reliable data on the earliest life on earth.

The Oldest Fish Fossils

The oldest fish fossils on record were found at Chengjiang, in Yunnan Province, China. Two species have been found dating from about 530 million years ago. Haikouichthys ercaicunensis, and Myllokunmingia fengjiaoa, are recent finds. If verified these finds will rewrite the fish chapter of evolution.

Oldest Fossil Beds

The oldest fossils of multicelled animals come from just two places on earth. The Burgess Shale formation in Canada was long regarded as the oldest fossil bed. The Burgess Shale was formed about 530 million years ago during the Cambrian period. Many early Cambrian Period fossils have been found there. The Chengjiang Deposits of China are thought to be even older than Canada's Burgess Shale. The fossils are found near the town of Chengjiang, in the Yunnan Province of China. This area appears to be about 15 million years older than the Burgess Shale formation.

Vermont Has seen the likes of many different fossils including The Vermont State Fossil. Vermont's state fossil, the beluga whale Delphinapterus leucas, has the unusual distinction of being the only state fossil belonging to a genus and species that is still living today! It hails from the last days of the Pleistocene Epoch, around 12,500 years ago, when the great glaciers were retreating and the weight of the ice had depressed portions of the land below sea level. As the glaciers melted, for around 2500 years an arm of the Atlantic Ocean known as the Champlain Sea extended into what is now New York and Vermont. It is in sediments laid down in this seaway that fossils of Delphinapterus leucas are found.

Since Delphinapterus still exists today -- restricted to a marine arctic microenvironment in the St. Lawrence estuary of Canada -- scientists know far more about it than they do about other state fossils. These whales are white as adults, sing to each other so loudly that they are nicknamed "sea canaries," and use echolocation to hunt. The name Delphinapterus means "dolphin without a wing," a reference to the lack of a dorsal fin.

The first bones of Delphinapterus were unearthed in 1849 by workmen constructing the first railroad between Rutland and Burlington. Because the bones were found near the small town of Charlotte, the specimen came to be known as the "Charlotte whale." For some time, there was disagreement about whether the whale was the same species as the living beluga, or a different, extinct species. It was finally determined that the species were equivalent, and that the name Delphinapterus leucas should apply to both. Nearly 125 years after the discovery of the Charlotte whale, in 1993, the Vermont State Legislature paid homage to the specimen by designating Delphinapterus leucas the state fossil, with the passage of Act No. 66.

If you are interested in learning more about fossils or staring your own collection of fossils you can visit your local library to find books that will point you in the right direction. You can also find fossil information online at www.fossilsforkids.com or you can go to Cool Jewels in Montpelier to find some very nice fossil specimens for sale which range in price from $2.00 $100.00 so ask your parents to take you over so you can start your own collection.