Fossils

By: Rachel

What are fossils?

The remains or impressions of a prehistoric organism preserved in petrified form or as a mold or cast in rock.

What type of rocks are fossils found in?

Fossils are most commonly found in sedimentary rocks, but all sedimentary rocks are not necessary fossiliferous.

Examples of rocks with fossils in them.

How are fossils formed?

Fossils are formed in a number of different ways, but most are formed when a plant or animal dies in a watery environment and is buried in mud or silt. Soft tissues quickly decompose leaving the hard bones or shells behind. Over time sediment builds over the top and hardens the rock.

Different types of scenarios......

First, there was a ammonite who lived n the ocean that was killed, and then covered by sand. Then, a fern tree fossil was found in soil that was now on top of the sand creating a rock layer. Next, a dinosaur bone was found in an exposed outcrop of rock and created a third layer to the rock. The rock hardened with pressure and was cemented together.