Who here loves big dinos? I know I do, because they’re awesome. And when talking about meat-eating dinosaurs, they didn’t get any larger than Spinosaurus. At least, we haven’t found any that did. But it’s not just size that makes Spinosaurus aegyptiacus an impressive species.
This dinosaur was first described around 1915 from fossils recovered in Egypt’s Bahariya Oasis. After these specimens were inadvertently destroyed by British bombs during the Second World War, it was almost lost to paleontologists. All that remained was a handful of written descriptions that its discoverers put together for their own use.
Today, our understanding of the species has been bolstered by additional fragmented findings in Northern Africa. The discovery of several related species in the UK, Brazil, and the Republic of the Niger has also proven invaluable in understanding Spionosaurus’ feeding and living habits. So let’s get talking about the largest carnivore we’ve ever found, the one and only:
Spinosaurus was a theropod dinosaur from the Spinosauridae family which lived during the Late Cretaceous, 95-70 million years ago.
The name (pronounced spine-oh-sore-us) comes from a distinctive structure on the animal’s back — a spiny or “sail-back” ridge. We know of other dinosaur species that sported a similar feature, such as Dimetrodon, so it’s not entirely distinctive to spinosaurids (dinosaurs related to Spinosaurus). Still, as is the case with all of them, we don’t really know what the purpose of these ridges was. Early theories proposed they helped maintain the animals’ body temperature inside an optimal range (a process known as ‘thermoregulation’) but these have largely been ruled out. Our best bet right now is that the spiny lizards’ spines were used more for display purposes, maybe for a bit of balancing, as well. Alternatively, it could have been used to intimidate potential threats, as it almost doubled the apparent body size of Spinosaurus when fully deployed.
Other distinctive features of this dino were its large but slender body, an elongated crocodile-like head, straight, conical teeth, and a paddle-like tail. It also had its nostrils next to its eyes, instead of the point of its snout. These features heavily suggest that Spinosaurus was a meat-eating aquatic dinosaur. The discoveries of other spinosaurids with fish scales in regions corresponding to their digestive tract further reinforce this notion. But these features don’t really point to an exclusively aquatic species.
We presume that Spinosaurus, and likely other related spinosaurids, were more likely semi-aquatic, living close to bodies of water but also hunting on dry land. It was a bipedal beast, with small front limbs (although not as stumpy as those of T-Rex). This layout would be better suited to walking on land or wading through shallow waters than swimming, which helped rule out a fully aquatic lifestyle.
Spinosaurus likely lived in humid environments near to water — think tidal flats, mangrove forests, rivers. Not very different from how crocodilians today spend their lives. As a top predator, there was virtually nothing in its environment that it couldn’t or wouldn’t hunt. Fish, turtles, other dinosaurs of all kinds, from flying pterosaurs to the swimming plesiosaurus, were probably on the menu. The shape of its teeth and position of its nostrils, however, suggest that it was mainly a fish-eating species.
Still, the species’ real claim to fame is its size. We estimate that Spinosaurus could grow to reach 13 to 18 meters (40 to 60 ft) in length at adulthood, although that estimate has been contested. Other sources propose lengths from 15 to 16 meters (49 to 52 ft). Part of the issue here is that we haven’t found any complete Spinosaurus specimen, which limits our ability to accurately estimate its dimensions. As for sheer mass, we believe they could reach between 7 and 21 metric tons — which, admittedly, is a large interval; but still impressive!
Based on these figures, Spinosaurus would be the largest terrestrial carnivore ever found. It would be comparable to (although larger than) other infamous carnivores such as T-Rex.
How we found it
Perhaps ironically for a semi-aquatic dinosaur, the first Spinosaurus fossils were discovered in the deserts of Egypt. The species was described based on this incomplete specimen by Ernst Stromer, a German paleontologist, in 1915. The actual discovery of the fossils was the accomplishment of Stormer’s assistant, Richard Markgraf, who unearthed them in 1912.
The specimens were taken to the Palaeontological Museum in Munich where they remained as part of the Bavarian State Collection of Paleontology until the Second World War. Heavy bombing of the city under British air squadrons in April 1944 led to the destruction of the museum and the precious, at this time singular, Spinosaurus specimen. For over four decades, the species was functionally lost to science. The only materials available that could provide any information on Spinosaurus were Stormer’s descriptions of the fossils.
Between the 1990s and 2000s, however, archeologists working in Morroco re-discovered the Spinosaurus. This is considered to be a different species, Spinosaurus maroccanus, although that is in no way a settled matter yet. Even so, these discoveries did go a long way towards helping us better understand the dinosaur’s history.
Spinosaurus fossils remain rare even to this day, and we’ve yet to find a complete specimen. Even so, reconstructions of its skeleton paint the picture of a frankly terrifying, lithe predator. T-Rex might dominate the public imagination through its brutal renderings from Jurassic Park, but you definitely wouldn’t want to meet a Spinosaurus out in the forest, either.