FOSSILS
Imagine you’re exploring a rocky hillside and spot something unusual sticking out of a stone – a spiral shell, a leaf imprint, or even a giant tooth! You may have just discovered a fossil, a piece of history that has been hidden for millions of years. Fossils are nature’s way of preserving clues from the past, showing us what plants and animals looked like long before humans arrived. But how do these ancient remains turn into stone? And what secrets can they reveal?
WHAT ARE FOSSILS? Fossils are the preserved remains, imprints, or traces of plants and animals that lived long ago. Unlike bones or shells we see today, fossils have undergone a process where minerals slowly replaced the original material, turning them into stone. Fossils come in many forms – some are as small as a grain of sand, while others, like dinosaur skeletons, can be bigger than a school bus! Not every ancient creature became a fossil. Fossilisation is a rare and special process that only happens under the right conditions. That’s why every fossil we find is like a precious puzzle piece, helping scientists understand Earth’s history.
TYPES OF FOSSILS: Fossils come in all shapes and sizes, but they generally fall into a few main categories:•
BODY FOSSILS – These include bones, teeth, shells and even entire skeletons that have turned into stone. They help scientists understand what extinct creatures looked like.•
TRACE FOSSILS – These aren’t actual body parts but rather evidence of how an ancient animal lived. Fossilised footprints, nests, burrows or even preserved poop (called coprolites) tell us about an animal’s behaviour!
Not all fossils are made of rock – some are trapped in other materials like amber or ice, preserving even the tiniest details of prehistoric life.
AMBER FOSSILS – Sometimes, small insects, leaves or even lizards get trapped in sticky tree sap, which hardens into golden amber over millions of years. These fossils give us a crystal-clear look at creatures from the past!•
PETRIFIED WOOD – When trees fall and get buried under layers of sediment, minerals slowly replace their wood fibres, turning them into colourful rock. Petrified forests exist around the world, showing us trees that grew millions of years ago.
WHAT CAN FOSSILS TELL US? Fossils are like nature’s history books, telling the story of how life on Earth has changed over time. By studying fossils, scientists (called palaeontologists) can:
RECREATE EXTINCT ANIMALS – Fossils help scientists figure out what dinosaurs, woolly mammoths, and other long-gone creatures looked like.
UNDERSTAND EVOLUTION – Fossils provide evidence of how plants and animals have changed and adapted over millions of years. For example, fossilised feathered dinosaurs helped prove that birds evolved from dinosaurs!
TRACK EARTH'S CLIMATE – By studying fossils, scientists can tell what Earth’s environment was like in the past. Fossils of tropical plants in Antarctica show that it was once much warmer!
DISCOVER NEW SPECIES – Every year, new fossils are found, revealing animals and plants that no one knew existed. Some are small, like ancient insects, while others are giant, like the Spinosaurus, the largest carnivorous dinosaur ever found!
FOSSILS DON’T JUST APPEAR OVERNIGHT – it takes millions of years for them to form! Here’s how it happens:
BURIAL IN SEDIMENT – When a plant or animal dies, it needs to be quickly buried in mud, sand or volcanic ash. If it’s left exposed, it will decay, and no fossil will form.
MINERAL REPLACEMENT – Over time, groundwater seeps into the buried remains. The water carries minerals that slowly replace the organic material, hardening it into stone.
PRESSURE AND TIME – Layers of rock build up over millions of years, preserving the fossil deep underground.
DISCOVERY – Erosion, earthquakes or digging by scientists eventually brings the fossil back to the surface, ready to reveal its secrets!
