Fossils - The Tracks Of Dinosaurs
How do we actually know, how the dinosaurs look like? At the time of the dinosaurs there wasn't anybody who could have written something down for us.
Fossils - Bones
Up to these days bones or strange tracks are discovered worldwide over and over again. These remains, the so-called fossils, tell scientists a lot about the appearance and the life-style of the animals. With a lot of luck a bone is still so well-preserved that you don't even know how old it really is. Unfortunately, such findings are only extremely seldom.
Fossils - Fossilized Bones
Far more often fossilized bones are found. In this case sand got in the gaps and the holes of the bone, then became hard and so fossilized the bones over the time. These fossilized bones also help to find out how the animal has looked liked.
Fossils - Bone Prints
However, it can also happen that holes are found in the ground which look like as if a bone had lain there a long time ago. The scientists think that the bone itself was enclosed by hard stone and has simply resolved then. If sand penetrates into such holes, a bone of stone forms from it after a long time. If the hole remains empty, only the impression of the bone can be found. Those leftovers help the scientists to get a picture of the animal the bone could have belonged once.
Fossils - Other Remains
In rare cases also impressions of the skin are found which help us to get a clue about whether the animal had scales, a fur or even feathers. Every now and then even animal tracks like footprints and eggshells or even whole eggs are discovered. With the help of those tracks we can find out how the animal has lived, what it has eaten, how fast it could run, whether it lived alone or in a herd, if it has looked after its young ones and so on.
Fossils - How A Fossil Originates
- A dinosaur dies nearby a lake or sea and shortly afterwards is covered with sand and mud. Then it starts to dissolve in its grave.
- All organic parts like skin and muscles decompose, only the bones and teeth remain or are are replaced by sand, which fossilize later.
- Millions of years later, mountains originate in the place a sea used to be. Rain and wind clear away the sand from the spot the fossil is buried over and over again.
- So after a very long time parts of the fossil become visible again or are discovered accidentaly because of intensive search.