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Dr. Hone and Holtz take an objective look at Spinosaurus has an aquatic predator. Gotta love it, another view, excellent read. From Abstract: "Here we assess the arguments about the functional morphology of this animal and the available data on its ecology and possible habits in the light of these new finds. We conclude that based on the available data, the degree of adaptations for aquatic life are questionable, other interpretations for the tail fin and other features are supported (e.g., socio-sexual signalling), and the pursuit predation hypothesis for Spinosaurus as a “highly specialized aquatic predator” is not supported. In contrast, a ‘wading’ model for an animal that predominantly fished from shorelines or within shallow waters is not contradicted by any line of evidence and is well supported. Spinosaurus almost certainly fed primarily from the water and may have swum, but there is no evidence that it was a specialised aquatic pursuit predator." https://palaeo-electronica.org/content/2021/3219-the-ecology-of-spinosaurus

A recent interpretation of the fossil remains Spinosaurus aegyptiacus proposed that it was specially adapted for a semi-aquatic mode of life—a first for any predatory dinosaur. To test some aspects of this suggestion this study developed a three-dimensional, digital model of the animal that incorporates regional density variations, lungs and air sacs, and the flotation potential of the model was investigated using specially written software. It was found that Spinosaurus would have been able to float with its head clear of the water surface, although it was laterally unstable and would tend to roll onto its side. The conclusion is that Spinosaurus was not highly specialized for a semi-aquatic mode of life. Furthermore, the floating characteristics of the Spinosaurus model were similar to those of models of other predatory dinosaurs, indicating that there was nothing special about the buoyant characteristics of this animal, and that other theropods could have successfully taken to water to the same degree as well. So Spinosaurus may have been specialized for a shoreline or shallow water mode of life, but would still have been a competent terrestrial animal. Interesting paper, very reputable and a big deal considering the source, The Royal Tyrrell Museum. Newspaper Article: Royal Tyrrell Research Blows Swimming Dinosaur out of the water https://calgaryherald.com/news/local-news/royal-tyrrell-research-blows-swimming-dinosaur-theory-out-of-the-water https://peerj.com/articles/5409/ Henderson DM. (2018) A buoyancy, balance and stability challenge to the hypothesis of a semi-aquatic Spinosaurus Stromer, 1915 (Dinosauria: Theropoda)PeerJ 6:e5409 https://doi.org/10.7717/peerj.5409

Although the paper is paywalled the abstract provides some interesting insights The hypothesized aquatic habits of Spinosaurus have been called into question, and the distribution of aquatic habits within Spinosauridae remain unclear. New spinosaurid specimens from the Kem Kem beds of Morocco reveal aquatic adaptations in the cranium. 1) Elevated orbits and bending of the frontals placed the eyes atop the skull, as in semiaquatic animals such as crocodiles and hippos. 2) Two morphologies are present, a smaller morph characterized by narrow, triangular frontals, and a larger morph characterized by broad, subrectangular frontals overlapping the prefrontals. The two morphs suggest two distinct spinosaurine taxa, and are tentatively referred to the spinosaurines Spinosaurus cf. aegyptiacus and Sigilmassasaurus brevicollis, respectively Another interesting point in the abstract: The appearance of giant semiaquatic dinosaurs may have followed the disappearance of giant pholidosaurid crocodylomorphs, suggesting that the extinction of large crocodylomorphs was associated with the rise of dinosaurs as apex predators in the freshwater ecosystem in North Africa. https://www.sciencedirect.com/science/article/pii/S0195667117303427 Aquatic adaptation in the skull of carnivorous dinosaurs (Theropoda: Spinosauridae) and the evolution of aquatic habits in spinosaurus Thomas M.S.Arden, Catherine G.Klein, SamirZouhri, Nicholas R.Longrich From outline images frontals are shown. @LordTrilobite

This paper looks to confirm the semi-aquatic lifestyle of Spinosaurids using oxygen isototopes in their bones. Direct evidence concerning spinosaurid diet was inconclusive since it appears that they also fed on dinosaurs and pterosaurs. Because of the shape of their jaw/teeth and fish remains in their stomach, the hypothesis of spinosaurs as “crocodile mimics” has been widely accepted. However, their postcranial anatomy differs relatively little from that of the usual large theropods, and is not particularly suggestive of aquatic habits. So the paper concluded that stable oxygen isotopes unambiguously show for the first time that some dinosaurs, i.e., the spinosaurid theropods, used freshwater environments more as a living habitat than just as temporary hunting grounds. W020120622356922971023.pdf