A game of death and chance

The exceptional quality of the preservation of this Tarbosaurus may give a false impression of the reality encountered in the field: during their excavation, palaeontologists are in fact often confronted with accumulations of bones of different origins that are sometimes difficult to identify. 

On the basis of geological maps and research carried out by colleagues, scientists identify areas that are likely to contain the remains that they are seeking: for example, in France, the site of La Voulte-sur-Rhône near Valence is renowned for the extraordinary preservation of deep-sea organisms dating to the Jurassic. The site of Canjuers in the Var is known for seashore species, also from the Jurassic, such as the little Compsognathus dinosaur which was found complete. The Museum’s palaeontologists also explore deposits in Namibia, Uganda, Uruguay, Turkey, China, Bolivia, Peru, Morocco, Laos, etc.

Once a study area has been divided into grid squares and planned, the exposed fossils are extracted from the rock. Originally vegetal or animal in nature, the samples can vary in size from a grain of pollen to the trunk of a petrified tree, from a tiny insect to the gigantic femur of a sauropod. Photographed and carefully packed, they are then transported to a laboratory to be cleaned and consolidated. For the smallest fossils, sieving is undertaken, followed by careful sorting using a binocular magnifier, which allows retrieval of the most microscopic specimens. 

Each discovery advances our understanding of the evolution of living creatures. Thanks to the material collected, palaeontologists name and classify the species found and then study their relationships (phylogeny), their ways of life and their environments. They are thus able to better define evolutionary relationships by combining the history of environments and climates and those of organisms that lived in geological periods. Finally, they are interested in anatomical innovations and the processes of adaptation that have emerged at various points in the history of life.