Experiments on ostrich decomposition and opisthotonus with implications for theropod dinosaurs

Abstract

Fresh ostrich cadavers were exposed in a natural environment (two on land and one in a shallow pool of water) to investigate decomposition and possible opisthotonus. The decomposition followed through to skeletonization of the ostrich cadavers by maggots, the primary agents of decay. During ostrich decomposition, tissue was consumed sequentially from the soft matrix tissue of muscles to fibrous and ligamentous tissue (both comprising collagen). The feathers (comprising β-keratin) were not consumed. The entire decomposition process was completed in 5 days. Towards the latter stages of the experiment, the cadavers on land showed stages of strong upward arching of the neck which fell short of the opisthotonic posture, while the cadaver in the pool showed the classic form of opisthotonus, strongly supporting the post-mortem hypothesis of the phenomena. Comparisons are made with opisthotonus in the theropod dinosaur, Sinosauropteryx.