By Nick Collins
Telegraph UK
A build-up of gas in the adults’ bodies as they decomposed could have built up to such a pressure that they burst open, causing their embryos and organs to fly out in all directions, it was widely claimed.
But now the “exploding dinosaur” theory, which became the most widely accepted answer to the prehistoric puzzle, has been debunked by Swiss scientists who demonstrated that the animals could not have acted as “natural explosive charges”.
More likely, they said, is the less exciting theory that mild currents on the seabed where the fossils were found were strong enough to sweep away the small embryonic bones but not large enough to dislodge the weightier mothers’ remains.
The exploding dinosaur theory dates back to 1976 when paleontologists sought to explain why skeletons of ichthyosaurs, marine dinosaurs from the early Jurassic period, had been preserved in almost perfect shape in German rock while their embryos’ bones were spread across the surrounding area.
Several similar fossils were identified and despite a lack of direct evidence “carcase explosion” became the most broadly accepted explanation for the bone distribution, being cited in dozens of scientific papers.
Now researchers based at Zurich and Basel universities in Switzerland say they have debunked the myth by proving that it would not have been possible for the gas, released as the bodies decomposed, to reach such pressures that it spontaneously exploded.
Through measurements of the corpses of 100 humans, which are of a similar size to ichthyosaurs, they found that putrefaction gases, which build up as the body breaks down, only reach pressures of 0.035 bar.
In contrast they calculated that for ichthyosaur skeletons to explode under 50 to 150 metres of water, the depth at which the fossils were found, would require internal gas pressures of between five and 15 bar, which would be extremely unlikely due to gas permanently seeping out of the body.