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Spinosaurus aegyptiacus is one of the most enigmatic and fascinating dinosaurs ever known to science. At 14 meters or 46 ft long and weighing just over 7 metric tons, it is by far one of the largest and heaviest theropods of all time besides Giganotosaurus, Tyrannosaurus and the contemporary Carcharodontosaurus and well as the type genus and species of the Spinosauridae, a family of crocodile-like theropods which were closely related to the Megalosaurids of the Jurassic and thrived in Africa, parts of Europe and Asia, and South America during the early Cretaceous. Spinosaurus lived around 100-94 million years ago during the Cenomanian Stage in and around the estuaries, mangrove swamps, freshwater rivers and streams, and tidal flats of what is now North Africa, from Egypt in the east to Morocco in the west, and the holotype fossils of the animal were described in 1915 by German paleontologist Ernst Stromer based on a partial skeleton from the Bahariya Formation of Egypt which preserved the lower jaw and much of the distinctly tall dorsal vertebrae which gave the creature its name and was housed in a museum in Munich. But they, along with most of the other fossils Stromer had collected, were destroyed in the spring of 1944 during the Second World War when the city was bombed by the Royal Air Force. Yet since the 1970s the discoveries of new Spinosaurus fossil material from the Kem Kem Beds of Morocco, such as a partial rostrum or snout along with the discoveries of much more complete Spinosaurids such as the European Baryonyx and North African Suchomimus, a near complete skeleton in 2014 which showed that the animal possessed unusually short hindlimbs compared to those of most other theropods, and the uniquely tadpole-like tail in 2020 have allowed paleontologists to paint a much more complete picture of this giant Cretaceous dinosaur’s skeletal anatomy. Some researchers have speculated that its tall neural spines were covered in a thin layer of skin and would have helped the animal to cool off in the balmy Late Cretaceous heat, much like the unrelated Permian synapsid Dimetrodon, while other researchers believe that such a speculative sail did not exist and that the spines were instead covered by a fatty dorsal hump, similar to that on a bison or camel, which would have helped the dinosaur store energy during the dry season. The dorsal sail, along with the paddle-shaped tail, might have also been brightly colored or patterned and used that way by male Spinosaurus to intimidate rivals of their own kind or to attract mates during the breeding season.

Isotope ratio analyses of the teeth of Spinosaurus compared with those of the much more terrestrial Carcharodontosaurus, the discovery of electro-receptors on the animal’s snout which allowed it to detect the vibrations of underwater prey, a paddle-shaped tail which was efficient for underwater propulsion and buoyant bones all indicate that Spinosaurus was a semi-aquatic piscivore that would have mainly preyed upon many of the large arapaima-sized freshwater fish of its watery habitat, such as the coelacanth Axelrodicthys, the gar Oniicthys, the bichir Bawitius, the lungfish Neoceratodus and the 4 meter (13ft) long Sawskate Onchopristis, either by chasing and catching them underwater like a crocodile or by waiting for them to come close to the shoreline and catching them that way like a heron. But since the semi-aquatic status of Spinosaurus and whether or not it fed like a croc or a heron has been heavily contested and debated among paleontologists these days, with some such as Nizar Ibrahim supporting the former theory and David Hone and Paul Sereno supporting the latter, there is no doubt that Spinosaurus was among the most aquatically-inclined of all dinosaurs and was highly adept at swimming across the rivers or waterways of its swampy estuarine habitat, and it and all the other dinosaurs of the Kem Kem disappeared from the fossil record when the whole area was flooded by the Tethys Sea during the Cenomanian-Turonian boundary event.

Ever since its pop-cultural debut in 2001 with the release of the third Jurassic Park film, Spinosaurus aegypticus has also become an increasingly frequent fixture of popular media involving dinosaurs, and has been featured in documentaries such as 2011’s Monsters Resurrected and Planet Dinosaur, NHK’s Amazing Dinoworld, and an episode of the 2025 in-name-only revival of BBC’s Walking with Dinosaurs where it was depicted in its scientifically-accurate form for the first time in a major Western Paleo-documentary.