The Dinosaur Opisthotonus Hypothesis
Scientists have postulated for years on the most likely reasoning behind the frequent positioning (opisthotonus) of many prehistoric dinosaur fossils in an extreme supine position, where the body exhibits severe hyperextension and a specimen’s head, neck and spinal column transform themselves into a complete backward arch. In the case of dinosaurs, scientists attempt to answer the primary cause of the apparently great number of dinosaur fossils which exhibit opisthotonus. The dinosaur opisthotonus phenomenon has been an official curiosity since 1859, when a researcher made notes in a document regarding a recently discovered specimen’s unusual death pose. In the years since, several specimens have been unearthed and discovered with the trademark twisted posture, head and neck recurved over the back of the animal.
Dinosaur Opisthotonus is a CNS Phenomenon
Opisthotonus (op-is-THOT-nus) is a Central Nervous System (CNS) phenomenon that occurs in live beings, and in death. There are many possible causes for this CNS failure, which results in the symptomatic or indicative hypertonic dystonia witnessed in many dinosaur fossils today. In broad terms, among them are heat stroke, disease (such as meningitis), and drowning, poisoning or other damage to the CNS. Among these, the primary locale of permanent damage is the cerebellum. The cerebellum is responsible for fine muscle movement and control. The cerebellum in affect controls the anti-gravity musculature of the body, enabling the maintenance of erect posture and cranial support. Any damage to the cerebellum could interfere with its ability to regulate the behavior of these anti-gravity muscles. When this happens, it is the muscles’ natural tendency to “pull”, thereby contracting and forcing the body arch and eventual contraction of limbs and mouth.
In dinosaur terms, the primary cause seems to be regarded as a single precursor—or, at least any studies seem to point in the general direction of one primary cause for all or most of the opisthotonus seen in dinosaur fossils. While causes of dinosaur opisthotonus can be as varied as traumatic brain injury, suffocation, severe cerebral palsy or tetanus, researchers want to remain open to all possibilities and actively pursue further understanding of the circumstances involved for all found specimens.
Volcanic eruptions (suffocation), attacks from predators (brain or spine damage, venomous poisoning), tetanus or meningitis (other infection?)….any of these could have resulted in the final backward arched opisthotonic death poses of any prehistoric dinosaur. Carnivorous Allosaurus has been found to have bone lesions similar to those found in bacterial infections that also cause meningitis. Could a bacterial epidemic have afflicted many of the carnivorous species of dinosaur? This would have been a terrible slow death for any creature, eventually unable to feed itself or defend itself against predation.
Dinosaur Opisthotonus and Modern Birds
Still—among dinosaurs—it has been noted in recent studies that dinosaur opisthotonis could be more specifically be related to the Ligamentum elasticum present in modern birds and, supposedly, in the ornithischian (bird-like) dinosaurs. These dinosaurs came equipped with a special ligament designed for the purpose of supporting a large and heavy tail and neck, or for a tail and neck that had to be very functional, as in flight or heavy support. According to this theory, the ligament simply presents its stored energy as post-mortem constriction, as the animal’s death diminishes the ability of the ligament to biomechanically control posture. This dinosaur opisthotonus would have happened at any cause of death.