August 20, 2012
Dinosaurs Got The Bends From Prolonged Diving
redOrbit Staff & Wire Reports - Your Universe Online
Dinosaur-like creatures may have injured themselves during leisurely deep-sea diving trips and not from ascending too quickly as previously thought
Bone deformities on the fossilized remains of Ichthyosarians, which were giant dolphin-like reptiles that first emerged approximately 245 million years ago, were identified in a recent study.
The lesions were like those that human divers get as a result of changes in body pressure, and suggest the reptiles suffered from a type of ℠the bends´.
A new analysis, by University of Melbourne pathologist Associate Professor John Hayman (0400 173 408), sought to explain what may have caused the bone lesions and is published in the latest edition of the Naturwissenschaften: Science of Nature journal.
That research argues the scarring is not from quick ascents as previously thought, but may be the result of deep diving and spending too long at depth which caused excess nitrogen to be dissolved in the body.
“Ichthyosarians probably evolved the ability to dive deeper and to remain at depth for longer periods,” Professor Hayman said.
“An alternative explanation is that the reptiles developed decompression sickness from being trapped in shallow water by predators.
“It wasn´t from sudden and rapid ascents,” he said.
The dangerous practice of deep sea diving wouldn´t have affected the reptiles´ long-term survival because any ill effects would have developed later in life, Associate Professor Hayman said.
“The lesions wouldn´t have been enough to kill the animal, and wouldn´t have affected it´s ability to hunt or breed.”
According to Professor Hayman, the new analysis was possible because the structure of the prehistoric reptiles' necks are very similar to the structure of modern humans´ necks.
“The arterial blood supply to the humerus and other bones such as the neck of the femur is highly conserved. It has remained much the same for 250 million years.”