Identification of the mineral phases

In general, the fossilization of living beings is a mineralisation process (the replacement of living tissue with mineral substances) in the sedimentary rock. As regards the diagenesis of bones, this is the result of physical, chemical and biological processes that modify the chemical and/or structural properties of fresh bone and determine its future in terms of destruction or preservation. (read Fossilization process of the Iguanodons) 

Through petrographic, mineralogical and chemical approaches, Thierry Leduc’s work has helped to identify some 30 different minerals in the Iguanodon bones. Some of these minerals formed during diagenesis, the main one being pyrite, which, as we have seen, is partly responsible for the bones’ fragility. Others formed after their excavation. Despite preservation treatments, contact with the ambient air and humidity led to the alteration of the pyrite and the formation of 16 different secondary minerals, including gypsum. Among other things, the growth of gypsum crystals is responsible for the appearance of cracks in the bones (read Formation process of minerals in bones).

The formation and growth of all these secondary minerals over time has caused, and continues to cause new fractures in the precious bones. It is therefore necessary to find new methods to protect them from deterioration. Thierry  Leduc’s work is helping to better understand the reasons behind the weakening of the Iguanodon bones. The development of new conservation techniques will require a great deal of consultation between researchers from other fields; the priority being to maintain the most stable and most suitable conservation conditions possible (temperature and humidity).

What were the Bernissart Iguanodons and what was their living environment?

Iguanodons belong to an extinct group of reptiles, the dinosaurs (from the Greek deïnos, meaning fearfully great, and sauros, meaning lizard). But they are now no longer considered as forming a natural group because not all the species can be included in the same phylogenetic tree with a common ancestor.