How fossils form

For ages 7–8, teach how fossils form as an ordered process story: an organism dies, is quickly buried in sediment, more layers pile on and press down, over millions of years sediment turns to rock while the organism's shape is preserved (often as minerals replace the material), and much later the rock is exposed and the fossil found. Two big ideas carry the most weight: burial must be QUICK (before the body rots or scatters) and fossilisation takes an ENORMOUS amount of time. Distinguish body fossils (shells, bones — shape preserved in stone) from trace fossils (footprints, imprints — evidence of activity). Link to prior learning that fossils occur mainly in sedimentary rock and that only once-living things fossilise. A driveable simulation of the process is proposed as the central activity, with sequencing/sorting practice, a retelling task, a tap-to-reveal cross-section, an optional excavation and expert Q&A, and a hands-on plaster-cast as complements. These are research-informed proposals, not validated interventions.

• 'Fossils are the actual bones/animal, unchanged' — not knowing minerals replace/preserve the shape in rock.
• 'Fossils form quickly' — missing the millions-of-years timescale.
• 'Any dead thing becomes a fossil' — not realising it needs quick burial and the right conditions (most don't fossilise).
• 'Fossils are found in any rock' — rather than mainly sedimentary rock.
• 'A footprint isn't a fossil' — not recognising trace fossils.
• 'Dinosaurs and fossils are the same thing' — conflating one example with the whole concept.

• A step-by-step fossil-formation sequence strip (die→bury→compress→rock→expose).
• Cross-section showing an organism buried under accumulating sediment layers.
• Body-fossil vs trace-fossil example cards (shell/bone vs footprint/imprint).
• A cast/mould demonstration (press a shell into clay, fill with plaster).

• Teach fossilisation as an ORDERED sequence (die → bury → layers build → turn to rock → exposed/found) and have children retell it in order.
• Foreground the two big ideas: quick burial (before decay) and immense time (millions of years).
• Distinguish body fossils (shape preserved: shells, bones) from trace fossils (footprints, imprints) with examples.
• Link to prior learning — fossils form in sedimentary rock, and only once-living things fossilise.
• Use vivid before/after imagery and, ideally, a hands-on 'cast' model (plaster over a shell) to make preservation-of-shape concrete.