Pterosaurs: dragons of the air
Pterosaur bones are usually easy to recognise as being pterosaurian as they possesses remarkably thin bone walls, but they can be confused with the bones of birds and small non-avian dinosaurs.
Often, identifying pterosaur bones relies on consulting scientific accounts from as far back as the 19th century. Here a pterosaur jaw bone from Brazil is compared to a small fragment of jaw bone from Cambridgeshire described by Sir Richard Owen in the 1870s. Despite being more than 100 years old, this volume is still a valuable aid for identifying pterosaur fossils.
Examining bones under a light microscope often helps to identify features such as muscle attachment scars and small holes where blood vessels and pneumatic diverticula (a system of airfield tubes that branched from the lungs) entered the bone, the positions of which can aid identification.
Some of the pterosaur teeth found in Morocco were sacrificed for destructive analytical procedures. Here, their internal structure is examined under a scanning electron microscope. For this they had to be sectioned with a diamond saw, etched in hydrochloric acid (HCl) and sputter-coated with a microscopically thin gold-palladium film.