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Spinosaurus: Amazing fish-eating predator of Early Cretaceous

The Spinosaurus, also known simply as Spino, was a carnivore that did not live at the same time as the Tyrannosaurus Rex, another famous Carnivore in the Mesozoic era. It got most of its “fame” from the third Jurassic Park movie and various books over the decades. At least, that’s when the public started knowing more about it. It lived in the early Cretaceous, whereas the T-Rex lived in the Late Cretaceous. They very likely never met, as it was a very long time between them.

The Spinosaurus lived in Northern Africa, whereas the T-Rex lived in North America. However, the Earth at the time was more of a singular landmass, rather than multiple separate continents. The Spino was discovered by fossil hunter Richard Markgraf & German paleontologist Ernst Stromer back in 1915.

Due to World War 1, the Spinosaurus Aegyptiacus (the “first” Spinosaurus fossil) became a casualty of war. The original fossils were destroyed in a British bombing raid in 1944. Fortunately, Ernst Stromer had left detailed drawings and multiple photographs, so the “type” remains available for analysis.​

Spino’s Size & Stature

The Spinosaurus was among the largest of all known carnivorous and piscivorous dinosaurs. It was larger than the T-Rex size-wise (though the T-Rex was larger in weight!). Various estimates suggest that the Spino ranged from around 41 – 59 ft (12.6 to 18 Metres), and was around 7 Tonnes (Some games like The Isle have Spinos as 9 Tons, which is a bit much in our opinion).

Its jaw was similar to that of a modern-day crocodilian. It had more useful arms than the T-Rex, being able to use them to help grab fish for its meals. The Spinosaurus’ tail, as recently discovered in 2020, has a more paddle-like design to it. Their forearms had an enlarged claw on the first digit, which helped them to hold their prey.

Like most theropods, it was originally thought to have stood up with its tail near the ground. But as science has advanced, both the Spinosaurus and other theropods like the T-Rex, Giganotosaurus, Acrocanthosaurus, and others were discovered to have had a more horizontal stance instead of a vertical stance.​

What’s With The Spinos Sail?

​The sail is an interesting aspect of the Spinosaurus. Some people may feel that it looks a bit odd, but it helped it to navigate lakes, oceans, and deep rivers with ease. This, along with its paddle-like tail, helped it be more agile in the water. It was bulky, so its swim speed may not have been the best, but it was able to quickly turn and bend to catch up to prey more easily.

Some theories say that the sail of the Spino may be what drew a female Spinosaurus to a male for mating purposes. It is said that the larger & more prominent the sail, the more favorable by females during the mating season. Stromer also speculated that the size of the neural spines may have differed in size between different genders. If you think of the Spinosaurus’ sail like a Peacock’s tail; you may consider that the males with the flashier tails are more attractive to females.

Another theory is it helped with maintaining their internal body temperature. During the day, it’s said to have absorbed the sun, and this helped perk up their metabolism, and at night, would have radiated excess heat. This theory came to be due to the Dimetrodon may have used it in this manner. The issue with this though is that evidence points to theropods being warm-blooded (endothermic). The more primitive Dimetrodon, though, was Ectothermic (cold-blooded).

A third theory was that it was used for navigation. This theory does make sense due to the new records, with its “new” tail design. Due to this, it would have helped it with swimming due to its semi-aquatic lifestyle. This theory seems more likely, to us at least.

The final theory is that it helped with survival. This theory states that it was more like a camel’s hump. It may have stored fat reserves it could draw upon. But this would mean another complete redesign of its sail, and a major overhaul in books, TV, and Movies. The trouble with this is that the Spinosaurus lived in the wet and humid forests of early-mid Cretaceous Africa.

The odds are that multiple of these theories were true. It may have been used for navigation, survival, and mating. Until more fossils are discovered, we may never fully understand how the Spinosaurus’ sail was used in their day-to-day lives.

Spinosaurus’ Aquatic Life

​Since the Spinosaurus is a Semi-aquatic dinosaur, it likely spent a good amount of time in or near water. Their sail and tail were critical for them to easily navigate the water due to their size. Its paddle-like tail, sail, and webbed feet must have helped them with swimming in their daily life. These three aspects of their body shape, indicate that they could swim similarly to other crocodilians.

They were likely very superb swimmers. They were not fully aquatic, like the Mosasaurus or Plesiosaurus, but they were in the water fairly often, which required them to have the body shape that they had during their entire lifespan.

Media & Games With Spinosaurus

​Multiple things have a Spinosaurus in them! Jurassic Park 3, ARK Survival Evolved, The Isle, Path of Titans, and more to come in the future, I’m sure! If you want to see my thoughts on the Spinosaurus in Path of Titans, watch the following video:


​The Spinosaurus is indeed an amazing dinosaur. Although they have had a lot of body changes over the years, their overall shape and design have pretty much stuck to be the same. The new spinosaurus tail design does feel legitimate and flows well with the rest of their body design. Let us know in the comments what your favorite parts of the Spinosaurus are!

If you want to see some more Spino content, check out my thoughts in the video link above, for the Path of Titans Spinosaurus! Have a rawrsome day, and we’ll see you next time in the Mesozoic Haven!

References & Notes

  • Thumbnail focus image by Orribec on Twitter/X (Used With Permission)

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Kenson M

Kenson M

Owner of Mesozoic Haven since 2015, when it was previously known as Jurassic Kingdoms. Is a family-friendly content livestreamer and lives in Texas.View Author posts

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