Water and death throes
Published: 8 January 2012 (GMT+10)
The Morrison Formation (lighter lower layers) at Dinosaur National Monument, Utah. [Click for larger image]
A great many dinosaur skeletons have been found around the world in what has been named “opisthotonic pose” i.e. the head thrown backwards, body arched and tail arched upwards. No one knows exactly why this death pose is so frequent, but theories have never lacked.
Many paleontologists believed dinosaurs died in water and the currents drifted the bones into that position.1 Veterinarians have rejected this theory which to them made no sense, even more so since the pose also was found in fossil birds and mammals. To test the water burial theory Faux made experiments on dead quails immersed in salt water and concluded they do not assume the opisthotonic pose. Faux and Padian therefore concluded that it is damage to the central nervous system, possibly caused by bacteria or some sort of intoxication, that caused the muscles to contract so peculiarly.
Allosaurus jimmadseni from Dinosaur National Monument, Utah. [Click for larger image]
Recent research reverses that conclusion.2 Scientists at Brigham Young University in Utah placed plucked chickens in cool fresh water and their necks arched and heads were thrown backward within seconds! Nobody knows why the two studies have yielded diametrically opposed results and whether salt plays a role in it, but it is being speculated.
There is another aspect regarding dinosaur fossils: besides their death pose, the sediments they are found in also reveal water deposition, usually in flooding conditions3 with the bones revealing violent transport.4 At Dinosaur National Monument in Utah there is a beautiful dinosaur skeleton in a classical opisthotonic pose—the predatory Allosaurus jimmadseni (Photo left). Not only is the animal’s head missing, but its tail is broken close to the body and lies parallel to the body under the feet with the thicker part right under the chest. Many other dinosaur fossils in the site’s quarry are found in the same opisthotonic pose and are headless.
Several hundred kilometers northeast, in Wyoming, in the Dana Quarry,5 in the same Jurassic Morrison Formation, a complete Allosaurus jimmadseni skeleton was found in 2007, on top of a Stegosaurus fossil, with the latter’s humerus almost inside the Allosaurus’ mouth. The two creatures died as they were fighting and were fossilized undisturbed! And all of this (as well as the Utah dinosaurs) happened in the Jurassic period (according to the evolutionary time scale) some alleged 85 million years before the infamous Cretaceous/Tertiary meteorite-induced catastrophic extinction of dinosaurs.
So let us summarize: many dinosaurs around the world had been fossilized in an unusual swirling position—opisthotonic pose—for which their immediate underwater burial is almost certainly required. Many dinosaur bones as well as sediments hosting them reveal violent water transport. Would it therefore be unscientific to postulate one big hydraulic catastrophe as the source of all these violent and instant killings? The one the Bible mentions in the book of Genesis …
- Sanders, R., Agonized pose tells of dinosaur death throes, UC Berkeley News, 6 June 2007; berkeley.edu/news/media/releases/2007/06/06_deaththroes.shtml. Return to text.
- Switek, B., Watery secret of the dinosaur death pose, New Scientist, 23 November 2011; www.newscientist.com/article/dn21207-watery-secret-of-the-dinosaur-death-pose.html. Return to text.
- Ryan, M., Russell, A.P., Currie, P.J. and Eberth, D.A., Taphonomy of a Centrosaurus (Dinosauria: Ornithischia) bone bed from the Dinosaur Park Formation (Campanian) of Alberta, Canada, Palaios 16:482–506, 2001. Return to text.
- Benton, M.J., Cook, E., Grigorescu, D., Popa, E. and Tall6di, E., Dinosaurs and other tetrapods in an Early Cretaceous bauxite-filled fissure, northwestern Romania 1, Palaeogeography, Palaeoclimatology, Palaeoecology 130:275–292, 1997. Return to text.
- Allosaurus vs Stegosaurs—the fighting pair, www.heardmuseum.org/attractions/exhibits/documents/19195_HGAN_FightingPairBro4_000.pdf; accessed 16 December 2011. Return to text.