This website is based on photographs of my fossil collection. The collection is not necessarily typical or complete, but it does show you the type of fossils that you can buy or find for yourself, plus a little about them.
The word fossil used to mean just something that was dug up from the ground. People had many ideas and stories about these strange stones with different shapes to normal stones. This website describes some of these folk tales. Finally, it was realised that these were parts of dead animals or plants which had been changed to stone, and this is now what we mean by fossils.
Fossils are very important. They help us to understand about animals and plants that lived in the past. They also help to date the different parts of the Earth. Rocks lie in layers. The upper layers are more recent than lower layers (unless something like earthquakes have turned them upside down). The Grand Canyon was made by a river cutting through many layers of rock, so when you walk down into the Grand Canyon, you are walking past increasingly older rock layers. Animals found in the same rock layer obviously lived and died at about the same time. Some animals alive today are not found in rocks 400 million years ago, such as birds. Some animals found as fossils in these ancient rocks are no longer alive today, such as trilobites. Some animals have been found as ancient fossils, and yet are still alive today, such as brachiopods.
Not all dead animals and plants become fossils, in fact, very few do. When an animal dies, usually it is eaten by a carnivore, or by creepy-crawlies, or fungus, or even bacteria. Even the bones may be chewed and broken up, or eventually rot away. To become a fossil, the animal must somehow be preserved from decay. The soft tissues, such as muscle and skin, decompose quickly, so it is extremely rare for these to be fossilised. Bones, teeth, shells are hard, and they have a chance. But even these must be covered by something to stop the oxygen in the air (or water) decomposing them. If a shellfish dies, it can drop into the soft sediment at the bottom of the ocean. If it is covered with this silt, it can get preserved. Eventually the silt gets changed to stone (or sedimentary rock, as it is called), and the shell may be replaced by a mineral and so become a fossil. If you look at the index of this website, you will notice that there are a lot of marine creatures, especially shellfish! It is harder for land creatures to get fossilised. There are tar pits made of liquid asphalt. Animals can get stuck here, and the asphalt can preserve them. They could also get sucked down by quicksand or mud. Insects sometimes get stuck in tree resin, which turns to amber. Land animals certainly have been fossilised, even feathers have, yet they are much rarer, and you are less likely to find such a fossil yourself, or be able to buy one cheaply. This also explains why the fossil record is not complete. We are lucky that we have as many fossils as we have!
Sometimes you don't see the original animal (or shell, bone or tooth), you see the impression. Perhaps the shell was resting on some mud, and you see the grooves of the shell in the sedimentary stone. Occasionally, you even get both the original and the impression. See the ammonite page for an example.
The photographs on this site are mostly quite large. This means that you can see details of the fossils. I give the real size in each case before the photo. This will be the length - the longest side. Sometimes the fossil is within a larger stone, and in that case I say which I am measuring. If you wish to use the photos, you can reduce them to the size that you want, which will improve the quality. Anyone may use any photo of these fossils for educational use, or private use. The specimens in the photos are of variable quality. The shop-bought specimens are much better than the ones that I found myself. I hope that people will be encouraged to find fossils for themselves, and if so, it's important to realise that they don't necessarily come complete, let alone nicely polished!
I am not an expert on fossils and I am afraid that I won't be able to identify any for you. I have bought fossils from shops and have managed to find a few. This explains the different levels of information that I give. Some sellers are highly knowledgeable, and told me the genus or species, and how old, and where it was found. Others seem to know nothing at all! When I found fossils, I got some of them identified by my local museum. I suggest you do the same.
© Jo Edkins 2007 - Return to Fossils index