What can fossils tell us? Fossils are our biggest clue to life on Earth before humans. They can help us understand what prehistoric animals and plants looked like and how they lived, as well as provide evidence for evolution. If you’re teaching your primary class about what we can learn from fossils, here are some ideas to get you started.
The shape and size of prehistoric animals and plants
It is generally the tough, or solid parts of an animal that can become fossils (shells, bones, teeth, scales). These body parts can reveal how big a creature was when it was alive. Even a single tooth or bone can help scientists estimate the size of the complete animal.
In 2021, a huge ichthyosaur fossil skeleton of a near-complete animal was discovered at Rutland Nature Reserve in the UK. Icthyosaurs were prehistoric marine reptiles. The fossil was 10 m long from head to tail! You can read more about the discovery here. This particular example is around 180 million years old, and as ichthyosaurs became extinct during the late Cretaceous period, fossils are the only clues that they ever existed.
What prehistoric animals ate
From animals dying mid-meal, to smooth gastroliths (stones swallowed to help digest food) found within the stomach area of dinosaurs, fossils can help scientists piece together ancient food chains.
Fossil whale bones have been discovered with chip marks made by megalodon sharks feeding on them – ouch! You can read about an example of whale bones found with megalodon damage here.
Sometimes, it’s fossil poop that can provide the clue! British fossil hunter Mary Anning was the first to notice this when she collected objects containing fish scales and bones from around the fossil skeletons of prehistoric ichthyosaurs. These objects were later called coprolites and confirmed to be fossil poo! You can find out more about coprolites from the Natural History Museum here.
Lifestyle and movement
Dinosaur footprints are known as trace fossils – they are not part of the animal itself, but something it has left behind. Footprints can reveal whether a dinosaur lived in a herd or alone, if it ran or walked, or if it moved on 4 legs or 2.
Evidence for evolution
Fossils show us that life on our planet was once very different! Many species that were alive millions of years ago have since become extinct, but their ancestors are alive today.
The rocks below us are formed in layers. Older layers of rock contain the oldest fossils, whilst new layers contain the most recent. The layers in which fossils are found create a timeline for when species inhabited the earth, and for how long. They also show which species lived together.
These layers can show changes in similar species over time. Some changes can be seen in detail, for example, the evolution of the horse or modern whales from their prehistoric ancestors. I like these videos of horse and whale evolution for kids.
There are some great children’s books that explain fossils and evolution in more detail. I wrote about these in a previous blog post.
Do fossils have all the answers?
Fossils can’t reveal all the animals that ever lived – some species of animal might never have become fossils. Skin and soft body parts quickly rot away so are very unlikely to fossilize.
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