"Caissons disease”

Well-known to divers, caissons disease, or decompression sickness describes a series of disorders affecting living beings that are exposed to sudden changes of pressure following deep dives and returns to the surface. This disease, studied in the context of histology has, for example, enabled paleontologists to understand that certain ichthyosaurs of the family of Baracromia, marine reptiles of the Mesozoic, could descend to depths of 500 meters. An out-gassing of nitrogen under the influence of a pressure lower than that which kept the gas in its liquid state caused necrosis of the bones near the cartilage causing distinctive holes. Observation of these necroses in the humerus of some communities of highly evolved Baracromia made such deductions possible.