Science · 3rd Grade

Active learning ideas

A Gallery of Fossils

Become a detective of the past! We're going on an adventure to uncover the secrets hidden in rocks and learn about the amazing creatures that roamed the Earth millions of years ago.

• Common Core State Standards
• NGSS: 3-LS4-1 - Analyze and interpret data from fossils to provide evidence of the organisms and the environments in which they lived.

• 30–45 min
• Pairs → Whole Class
• 3 activities

Activity 01

• Stations Rotation
• 45 min · Pairs

Create a Fossil

Students press a small object, like a shell or toy dinosaur, into modeling clay to create a mold. They then pour plaster of Paris into the mold and let it dry to create a cast fossil, directly experiencing how these two types are related.

Compare body fossils, like bones and teeth, with trace fossils, like footprints and burrows.

Facilitation Tip

Have students write down a prediction of what their cast fossil will look like before they remove the clay.

What to look for

Use an exit ticket where students must sort a list of fossils (e.g., 'dinosaur tooth,' 'footprint,' 'leaf impression') into two columns: Body Fossils and Trace Fossils.

• Remember
• Understand
• Apply
• Analyze
• Self-Management
• Relationship Skills

Activity 02

• Stations Rotation
• 30 min · Small Groups

Fossil Dig Simulation

Bury various 'fossils' (small plastic skeletons, shells, and even items to represent trace fossils like hardened clay 'footprints') in a sand table or individual plastic bins. Students use brushes and tools to carefully excavate the items, recording their findings like a paleontologist.

Explain how a mold fossil is different from a cast fossil.

Facilitation Tip

Encourage students to map their dig site on paper first to practice systematic observation and recording.

What to look for

Students create a 'Fossil Field Guide' booklet. Each page features a drawing of a different type of fossil, its name, and one sentence explaining what it tells us about the ancient organism.

• Remember
• Understand
• Apply
• Analyze
• Self-Management
• Relationship Skills

Activity 03

• Stations Rotation
• 40 min · Small Groups

Fossil Inference Stations

Set up stations with pictures or replicas of different fossils (a T-Rex tooth, a trilobite, a leaf impression, a footprint). At each station, students answer questions on a worksheet, such as 'What part of the organism was this?' and 'What can this fossil tell us about how the organism lived?'

Identify which type of fossil would tell you more about an animal's behavior.

Facilitation Tip

Provide sentence starters at each station to help students formulate their inferences, such as 'This fossil tells me... because...'

What to look for

Provide students with a 'Fossil Facts' checklist of the key learning objectives. Students use smiley faces or a simple color code to indicate their confidence level for each statement.

• Remember
• Understand
• Apply
• Analyze
• Self-Management
• Relationship Skills

A few notes on teaching this unit

Start with concrete examples, using high-quality images or real fossil replicas to introduce body and trace fossils. Use think-pair-share to have students brainstorm what a fossil footprint might tell them versus a fossil tooth. The hands-on activity of making a mold and cast fossil is crucial for cementing the difference between these two related concepts.

Students will be able to identify different types of fossils and explain what clues they give us about ancient life, from what a dinosaur ate to how it walked.

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Watch Out for These Misconceptions

• All fossils are dinosaur bones.

  Fossils are the preserved remains or traces of any organism from the past, including plants, shells, insects, and fish. Dinosaur bones are a famous type of fossil, but they are only one small part of the fossil record.

• Fossils are the actual, original bones or shells of an animal.

  Most fossils are not the original material. Over millions of years, water seeps into the bone or shell and deposits minerals that gradually replace the original organic matter, creating a rock-like copy.

• Humans and dinosaurs lived at the same time.

  The last dinosaurs died out about 65 million years ago. The earliest human ancestors appeared only a few million years ago, so there is a huge gap in time between them.

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Methods used in this brief

• Stations Rotation