SPARK July 2014 | Page 12

Fantastic Fossils The only way we have of learning about dinosaurs is by studying fossils. Fossils are the remains of ancient animals and plants and they have been found on every continent on Earth. For remains to be considered fossils, scientists have decided they have to be over 10,000 years old. There are two main types of fossils - body fossils and trace fossils. How Are Fossils Made? To investigate how fossils are made, we are going to look at an example of a fish! The animal dies and its e body is washed down th ft river, where it lays on so ckly. mud and is buried qui Then, all the muscle and flesh rot away from the skeleton, leaving only the bones behind. These drift apart over time. After mil ions of years the surface of the Earth changes, with mountains rising over the area where the sea once was, and these then in turn get worn down by extreme weather. ins e the rema s ar Trace fossil of an animal, ity of the activ ways, fossilized ck such as tra ts, footprints s gg shel s, ne (fossilised e d coprolites an osaur poo!). din Now, due to changes on the Ea rth's surface, the sea now covers th e area where the river once wa s. Pressure from the sea is turn ing the sand into sandstone. Body fossils are the remains of a pla nt or animal's body. 12 | SPARK Now the mountain area is a desert, and a tip of the fossilised bone is revealed. Palaeontologists now uncover the rest of the animal, revealing all the fossilised bones. 13 | SPARK