Since its monumental appearance in 2001, people have had many questions about Spinosaurus: what did it look like, what did it eat, what’s up with the sail? Scientists have tried to answer as many of these questions as possible, but there is little known about this misunderstood dinosaur.
Spinosaurus has, since its discovery, been a contender for the largest theropod dinosaur. Friedrick von Huene (1926) and Donald Glut (1982) listed it as the greatest theropod (in terms of mass) in their surveys. Spinosaurus was upwards of 49 feet in length and up to 6 tonnes in weight. Gregory Paul listed Spinosaurus as the longest theropod in 1988 but only considered it to have a mass of 4 tonnes. However, since no complete skeleton has ever been discovered, this estimates have been made on comparing the skull of Spinosaurus to other theropods which have been thoroughly documented.
Spinosaurus has a distinctive, and as yet confusing, spine. Neural spines growing out of the back created the ‘sail’ which could reach as tall as the length of the skull. The use of the ‘sail’ is unknown, with some scientists claiming that it regulated body temperature (thermal regulation) while others are convinced that it served a much different purpose; including part of a hump structure to store fat like a camel or bison, or as display for mating purposes.
Other dinosaurs of the area, namely Ouranosaurus, possibly had similar features which would suggest an environmental reason for the existence of the ‘sail.’ It is also a possibility that the ‘sail’ was analogous to the spine of the synapsid, Dimetrodon. Scientists simply don’t know, they’re not sure if it served just one purpose or multiple purposes.
The skull of Spinosaurus suggests that its diet primarily consisted of aquatic fauna (making it a piscivore), in that it was long like that of modern crocodiles with nostrils positioned close to the eyes and the lack of serrations on the teeth is evident that its jaws were for grabbing and holding rather than tearing. A recent study of the skull performed by Andrew Cuff and Emily Rayfield showed that Spinosaurus regularly preyed on fish more than land-based animals. In the end, scientists agree that Spinosaurus was probably opportunistic.
Two separate species of Spinosaurus has been discovered; Spinosaurus Aegyptiacus and Spinosaurus Moroccanus. Richard Markgraf discovered S. Aegyptiacus in 1912 and it was formally named by Ernst Stromer in 1915; though these initial fossils were destroyed in WWII. Dale Russell discovered S. Moroccanus in 1996, claiming that a difference in vertebrae length was sufficient for naming a second species; though most paleontologists have been torn on the issue (it’s impossible to compare since S. Aegyptiacus were destroyed).
The posture of Spinosaurus has come into question often; it is hard o determine since bones can only determine how an animal moved but not necessarily how it moved in any given position. It is likely that Spinosaurus was both bipedal (walked on two legs) and quadrupedal (walked on legs and arms), based on need. The hypothesis that they were exclusively quadrupedal is less-likely since theropods, in general, couldn’t rotate their forearms so that their palms faced the ground but it is extremely likely that they could rest on their forearms.
Spinosaurus lived 112 to 97 mya (million years ago) in what is now northern Africa. Little is actually known about the area, which is one of the reasons parts of the Spinosaurus are unclear, though it is generally accepted that the land was similar to a mangrove swamp inhabited by several large predators (including Carcharodontosaurus), suaropods (including the titan Paralititan) and ancient crocodiles. Seasonal changed would’ve been likely and meant that Spinosaurus would’ve been forced to change some of its dietary habits; though the abundance of large fauna in North Africa suggests that niche partitioning took place just like it does in the modern African savanna.
Spinosaurus garnered a modicum of fame when it appeared in the 2001 film Jurassic Park III, replacing the Tyrannosaurus Rex. Spinosaurus also appears in many books about dinosaurs, though only recent discoveries have allowed it to be represented with any accuracy, and on the postage stamps of a few African nations.
Spinosaurus was truly unique and misunderstood as people try to put the pieces together to form a picture of the real Spinosaurus. It will never reach the level of fame that Tyrannosaurus Rex has achieved, but it will always be admired and respected as one of the greatest dinosaurs to have ever walked the Earth.