3-LS4-1: Reading Fossils for Clues About the Past
Also called NGSS 3-LS4-1 · Topic: Interdependent Relationships in Ecosystems: Environmental Impacts on Organisms · Life Science
The Official Wording
Analyze and interpret data from fossils to provide evidence of the organisms and the environments in which they lived long ago.
Clarification statement: Examples of data could include type, size, and distributions of fossil organisms. Examples of fossils and environments could include marine fossils found on dry land, tropical plant fossils found in Arctic areas, and fossils of extinct organisms.
Assessment boundary: Assessment does not include identification of specific fossils or present plants and animals. Assessment is limited to major fossil types and relative ages.
NGSS Lead States, 2013 · Read it on nextgenscience.org · checked October 15, 2026
What 3-LS4-1 Means in Plain English
Third graders study fossils as data: what kinds there are, how big they are and where they turn up. From that evidence they figure out which living things existed long ago and what the land was like, such as sea creature fossils sitting far from any ocean today.
Students sort fossils into broad groups, like shells, plants or bones, and compare older and younger layers, but they do not need to name exact species. This connects to rock layers in 4-ESS1-1 and to the fossil record in MS-LS4-1.
3-LS4-1 I Can Statements
- I can sort fossils into groups by type.
- I can use fossils to tell what lived long ago.
- I can explain what fossils show about where they formed.
3-LS4-1 Worked Example
A sorting task with a tray of real fossil pieces from the limestone around Cincinnati, Ohio.
What was the land around Cincinnati like when these fossils formed?
Set It Up: A tray of small fossil pieces from Cincinnati-area limestone, magnifying glasses, sorting cups, and a tally sheet.
- Look at each piece with a magnifying glass and describe its shape.Ridged shells, twig shapes, stacked disks
- Sort the pieces into cups by shape.4 groups
- Tally each group.Shells 18, twigs 9, disks 7, horn shapes 3
- Match each group to picture cards of today's sea animals that look similar.All 4 groups resemble ocean animals
- Check a map: how far is Cincinnati from the ocean today?Hundreds of miles inland
Every fossil group came from a sea animal, so a shallow sea once covered the land around Cincinnati, about 450 million years ago.
Why it works: Fossils keep the shapes of living things where they lived and died, so sea fossils on dry land show that water once covered that place.
Common Mistakes with 3-LS4-1
Thinking fossils are the actual animal
“This is the real shell, just old.”
Try this: Explain that many fossils formed as minerals slowly replaced or filled the shell, so they are rock copies of the shape.
Assuming a place always looked the same
“Ohio has always been land.”
Try this: Point to the sea fossils as evidence. Animals that need ocean water could only live there if water covered the land.
Mixing up older and younger layers
Calling the top layer of a cliff the oldest
Try this: Remember that layers pile up over time, so in undisturbed rock the deepest layer formed first and is the oldest.
Where 3-LS4-1 Fits
Practice 3-LS4-1
Quick Check
- Fish fossils are found in a desert. What does that tell you?
- Why do scientists sort fossils into groups?
- In a stack of rock layers that has not been moved, which layer is oldest?