Do you ever wish you had a time machine, where you could travel back and see giant dinosaurs, fantastical sea creatures and long extinct flowers and plants? Have you ever wondered how scientists and historians know so much about what our planet was like millions of years ago? The good news is you can go back in time, to see and touch long extinct life. Welcome to the wonderful world of fossils!
Fossils are the remains or traces of ancient life, which have been preserved in rock. Examples of fossils include bones, shells, leaves, imprints of animal footprints, skeletons, trees, in fact just about anything living you can think of.
Fossils are formed when a plant or animal dies and is quickly buried by sediment, such as mud, sand or volcanic ash. The soft tissues decompose, leaving behind bones, shells or even just the imprint of the plant or animal. Over thousands of years more sediment builds up over the top of the buried organism, and eventually all the layers harden into rock. Millions of years later erosion causes these rocks to be worn away, and the fossils are revealed!
Fossils come in all shapes and sizes. In the UK, the largest fossil discovered is a 33ft (10m) long ichthyosaur and is about 180 million years old. It was found in 2021 at Rutland Water Nature Reserve.
In Australia, the fossil of a giant dinosaur was discovered. The “Australotitan cooperensis” was about 100 feet (33 m) long and 21 feet (7m) tall. It weighed somewhere between 25 and 81 tons. For comparison, a Tyrannosaurus rex was only about 40 feet long and 12 feet tall!
At the other end of the scale, an international team of scientists recently discovered the smallest dinosaur ever found. The skull of a tiny dinosaur was trapped in 99-million-year-old amber from Myanmar and is only a few centimetres long.
Microfossils of things like bacteria or pollen also exist and are only visible through a microscope.
Everyone knows that fossils are a record of ancient life, but just how old are they? The generally accepted definition of a fossil is that it must be at least 10,000 years old, however many are a lot older, up to 3.4 billion years old! The Natural History Museum (NHM) in Los Angeles has an amazing collection of fossils, including some from the La Brea Tar Pits that are between 10,000 and 50,000 years old. According to the NHM:
“The La Brea Tar Pits fossils may sound pretty old, but not if you talk to someone in the Vertebrate Palaeontology Department. They deal with fossils that are millions of years old, like 6-million-year-old bone-crushing dogs (and their poop). And then there is the Dinosaur Institute, which has many fossils older than 100 million years. And even that, while definitely old, is nothing compared to some of the specimens in Invertebrate Palaeontology. They have a few fossils that are billions of years old!”
Palaeontology is the study of the history of life on Earth, based on examining fossil evidence. Palaeontologists use fossil remains to understand different aspects of extinct and living organisms including plants, animals, fungi, bacteria, and single-celled life forms. To become a professional Palaeontologist, you are likely to need a degree in botany, Earth sciences, geology, palaeontology, or zoology. However, many people simply study and collect fossils as a hobby.
Fossils can be found almost anywhere where there are rocks! A lot of fossils are found on beaches, where the tide washes in rocks and coastal erosion causes cliffs to wear away. Farmers’ fields and quarries can also be a good place for fossils, but you will need permission to enter private land.
If you are lucky enough to be near a beach, simply walking along the foreshore and shingle can reveal fossils that have been washed in from the seabed or other locations. Charmouth, Bognor Regis and Harwich are famous fossil hunting beaches in the UK.
Inland quarries, scree slopes and coal spoil heaps can often be a great place to look. Streams and riverbanks too, where fossils are washed up from the riverbed, or have fallen from nearby cliffs. You may even find fossils in your own garden, especially if you are doing some digging work.
You can start to collect fossils just by using your eyes and hands, however there are some other tools commonly used:
Always wear a good pair of protective goggles when using any striking tools and keep children under close supervision. Taking photos with your GPS enabled smartphone will help record the location of your find.
The rules for collecting fossils are a mixture of legal, safety and best-practice considerations. Fossil Collecting Codes are often created to cover the characteristics of a given site. The Charmouth Heritage Coast Centre has an excellent Fossil Collecting Code that covers the Jurassic Coast in Dorset, for example.
There will also be local rules and procedures for reporting significant fossils, for example uncovering what may be a small part of a much larger fossilised animal. Please abide by the local rules, to ensure your own safety and the enjoyment of fossil hunting for all.
Finding your first fossil is a priceless experience, but fossils do have a financial value too. The most expensive fossil in the world is an unusually complete Tyrannosaurus rex called Stan, which sold for a staggering $31.8 million USD at an auction recently.
Fortunately, not all fossils cost that much. For those looking to buy fossils, excellent examples are surprisingly affordable. People often buy fossils as gifts or to start their own collection.
Because fossils are rock, they tend to be heavier than bone, so if the object you have found is heavy, it might be a fossil. Many fossils tend to be darker in colour too, helping to distinguish them from the bone of a dead animal. On beaches, the markings and shape of a rock will help tell a fossil apart from an ordinary stone. The UK’s Natural History Museum offers an excellent free app, which can help identify and record the fossils that you find.
Fossils are an amazing record of the Earth as it was millions of years ago. Collecting fossils is a growing hobby, enjoyed by people of all ages. If you have any questions about fossils or want to add to your collection, please get in touch.
