Stefansic Fossil Lesson

Fossils

Fossils are
the traces or
remains of
organisms
that lived long
ago.

Many fossils are the remains of plants and animals that are extinct.

Extinct means they are no longer living and none are left on Earth.

Fossils have been found on every continent in mountains, under water, in valleys, ice, and many more places.

Paleontology

Paleontology is the study of fossils and about life from long ago.

Paleontologists estimate that only a small percentage of dinosaurs and other animals or plants that ever lived have been or will be found as fossils.

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Most plants and animals decompose quickly, especially in moist, warm places.

The circumstances have to be just right over a very long period of time for a fossil to form

Multiple Select

Check all of the true statements

• Organisms often become fossilized when they die.

• It is rare for an organism to become fossilized.

• Most organisms decompose quickly when they die.

• The circumstances have to be just right over a long period of time for a fossil to form.

• organisms tend to decompose especially quickly in warm moist place

The bones and teeth are hard mineral parts of an animal that are more likely to become fossils than soft parts.

Soft parts decompose quickly after an animal dies. The animal's body is buried in mud or other sediment and the teeth and bones do not rot like the rest of the animal's body.

After a long time, the chemicals in the buried animals' bodies undergo many changes. As a bone slowly decays, water filled
with minerals seeps into the bone and replaces the chemicals in the bone with other minerals that are as hard as a rock. Fossilization is the name of this process.

One type of fossil is the remains of the dead organism or the imprint left by the remains.

A second type of fossil is something that was made by the animal while it was living but has turned into stone. These are called trace fossils

Fossils come in many colors and are made of many different types of minerals, depending on where fossilization took place.

Most fossils are dug up from sedimentary rock layers.

Sedimentary rock is rock that has formed from sediment, like sand, mud, and small pieces of rocks.

Small pieces of an animal's remains become squeezed between the layers of this sediment. Over long periods of time, they are buried under more and more layers of sediment that piles up on top of it.

Multiple Select

Which of the following can be discovered by examining the fossil footprint of an animal?

• Speed of the animal

• Number of feet it walked on

• Bone structure

• All of these

Multiple Select

Which of these are one of the 4 main types of fossil? Check all that are correct.

• Mold

• Cast

• Petrified

• True Form

• Ancient

Molds and casts-

visible shapes that are left behind when an organism is buried in sediment.

Drag and Drop

When an organism leaves an impression of its body in the rock, that is called a _​ ​

Placeholder

fossil. If the mold gets filled in and filled with minerals, that is called a _​

Placeholder

fossil

Drag these tiles and drop them in the correct blank above

mold

cast

trace

Original remains/ True Form Fossils
Ice - can preserve the entire organism intact

Amber- organism gets stuck in tree resin
that hardens

Tar organisms get stuck in pools of tar

Multiple Choice

Original form remains can happen in which of the following?

• ice

• amber

• tar

• sedimentary rock

Multiple Choice

In undisturbed sedimentary rock layers, older fossils will be on the bottom and younger ones towards the top.

• true

• false