When were the first dinosaurs discovered?

Many people must have noticed old bones in the ground, but they did not attract much attention. In the 1500s dinosaur fossils were thought to be the remains of animals or human giants that had perished in the Biblical flood.

The first proper scientific investigation took place after a huge pair of jaws was unearthed in the Netherlands in 1770. The jaws were identified by the great anatomist Cuvier, who recognized them as the remains of a marine lizard. The creature was christened ‘Mosaurus’. Many other fossil finds followed, and by 1830 five major groups of extinct reptiles had been recognized.

Why do palaeontologists disagree about dinosaurs?

Scientists have found very few examples of some of the more interesting and puzzling types of dinosaur. It is very rare to find a complete skeleton, and even rarer to find other clues, such as the animal’s last meal or traces of its fur or feathers.

As a result, palaeontologists often guess at the appearance of an extinct animal, based on a few clues and on similar living animals. This method leads to strong disagreements. For example, some experts say that dinosaurs must have been warm-blooded, in order to move quickly and to live in such varied habitats. Others insist that they were cold-blooded animals, like modern reptiles.

How are dinosaurs preserved and reconstructed?

It is rare that you can just pick up dinosaur bones. They are usually embedded in very hard rock, and it can take weeks of painstaking work to chip them out carefully and release the whole skeleton. Usually the bones were scattered before fossilization, so palaeontologists often have to excavate a wide area around the first finds in order to make sure that they have not missed any important parts. The remains may be taken to a museum still embedded in a block of stone. Once the rock is removed, the fossil bones are reconstructed on a metal frame. These bones have now turned to stone and so they are very heavy and brittle. As a result many museums make castings of the bone in plastic, which can then be jointed together for display.

Picture credit: google