Paleontology 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.

For this activity, we used salt dough to create our very own fossils. Because we discussed stegosauruses this week, our fossils consisted of this special dinosaur. A few students also selected the spinosaurus for their fossil. To prep, we talked about what a fossil is. We then practiced placing a variety of dinosaurs into the salt dough to see what kinds of indentations they would leave. Finally, we chose the one we wanted to take home, and then allowed them to harden in the toaster oven!