Contributions to a Discussion of Spinosaurus aegyptiacus as a Capable Swimmer and Deep-Water Predator.

Jan Gimsa,Ulrike Gimsa

doi:10.3390/life11090889

Jan Gimsa, Ulrike Gimsa

Open Access

https://doi.org/10.3390/life11090889

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Abstract

The new findings on Spinosaurus’ swim tail strongly suggest that Spinosaurus was a specialized deep-water predator. However, the tail must be seen in the context of the propelled body. The comparison of the flow characteristics of Spinosaurus with geometrically similar animals and their swimming abilities under water must take their Reynolds numbers into account and provide a common context for the properties of Spinosaurus’ tail and dorsal sail. Head shape adaptations such as the head crest reduced hydrodynamic disturbance and facilitated stealthy advance, especially when hunting without visual contact, when Spinosaurus could have used its rostral integumentary mechanoreceptors for prey detection. The muscular neck permitted ‘pivot’ feeding, where the prey’s escape abilities were overcome by rapid dorsoventral head movement, facilitated by crest-mediated lower friction.

Highlights

Its discoverer, the German paleontologist Ernst Stromer (1871–1952), was perplexed by the large predatory dinosaur Spinosaurus aegyptiacus [1]
The fossil remains that he excavated in the Sahara were in a puzzling disproportion to the known anatomies of large predatory dinosaurs
Our new hypotheses will not be easy to prove. It should be checked whether they are compatible with new fossil evidence and hydrodynamic studies of extinct and extant creatures

Summary

Introduction

The German paleontologist Ernst Stromer (1871–1952), was perplexed by the large predatory dinosaur Spinosaurus aegyptiacus [1]. The fossil remains that he excavated in the Sahara were in a puzzling disproportion to the known anatomies of large predatory dinosaurs. Stromer found many remains of aquatic and swamp animals. Other large predators such as crocodilians made the areas unsafe, despite the low number of major terrestrial herbivores [2,3]. Taquet [4] and has intensified since 2014 when Ibrahim et al [5] suggested a semi-aquatic lifestyle, similar to Amiot et al [6], who argued that oxygen isotopes suggest that other spinosaurids that are closely related to Spinosaurus, were probably aquatic.

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