An Ultimate Guide to Spinosaurus: The Spined Lizard

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NameSpinosaurusDietCarnivorous/Piscivorous (Fish-eating)
Name Meaning“Spine lizard”Height4.3 meters (14 feet) at the hip
PronunciationSpy-no-SAWR-usLength12–18 meters (39–59 feet)
EraMesozoicLate CretaceousWeight7 to 20.9 metric tons (15,400 to 46,000 lbs)
ClassificationDinosauria,‭ Saurischia & TheropodaLocationNorthern Africa (Morocco, Egypt, Tunisia)

Spinosaurus Pictures

Spinosaurus | Warpaintcobra via Getty Images

The Spinosaurus

Gage Beasley Prehistoric's Spinosaurus Concept
Gage Beasley Prehistoric’s Spinosaurus Concept

Spinosaurus is an extinct genus of spinosaurid dinosaur that lived during the Late Cretaceous Period. 

Named for its estimated six-foot-long spines, it was alive between 99 and 93.5 million years ago. 

It inhabited the present-day Sahara region in North Africa, an area once covered by an extensive river system. 

It shows several features that suggest it was well-adapted to an aquatic or semi-aquatic lifestyle. 

It had crocodile-like jaws, which were ideal for a piscivore diet. Based on current size estimates, it is arguably the largest carnivore dinosaur to have ever lived on the planet. 

Spinosaurus was first discovered more than 100 years ago by German Paleontologist Ernst Stromer. 

Gage Beasley's Prehistoric Shirt Collection
Gage Beasley’s Prehistoric Shirt Collection
Gage Beasley's Prehistoric Plush Collection
Gage Beasley’s Prehistoric Plush Collection

Unfortunately, the fossil was destroyed in a bombing raid in 1944 during World War II.

Since then, only a handful of skeletons have been discovered, leaving a lot of gaps in Spinosaurus research.

Our understanding of this massive dinosaur has changed considerably in recent years, with ongoing research uncovering many new facts about it. 

In this article, we’ll discuss some of these discoveries and other interesting facts about the Spinosaurus

Physical Characteristics

Gage Beasley Prehistoric's Spinosaurus Size Comparison Chart
Gage Beasley Prehistoric’s Spinosaurus Size Comparison Chart

Spinosaurus is considered one of the largest known carnivorous dinosaurs

While size estimates for this dinosaur vary, it is generally believed to have reached lengths of about 40 to 50 feet (12 to 15 meters) and may have weighed between seven and 20.9 tonnes. 

This would mean that it was slightly longer and heavier than the infamous Tyrannosaurus rex and other large theropods of the Cretaceous Period, such as Giganotosaurus and Carcharodontosaurus

The Spinosaurus’ skull was shaped like that of a crocodilian. It was long—about 1.75 meters (5.7 feet)—and narrow. 

The rest of its body was also elongated and streamlined, suggesting that this dinosaur was adapted to an aquatic lifestyle. 

The most distinctive feature of this dinosaur was the hump-like structure on its back. 

Gage Beasley Spinosaurus Plush Toy
Gage Beasley’s Spinosaurus Plush Toy

The impressive 1.5-meter-tall sail was formed by neural spines that grew out of the dinosaur’s back vertebrae. 

The exact purpose of this sail is still debated, but it might have played a role in thermoregulation, display, or buoyancy control while swimming. 

The sail was thin and was probably covered in skin or some other soft tissue. 

The hip bone of the Spinosaurus was significantly small compared to that of other giant theropods. 

Its forelimbs were longer than those of most theropods, but the hind limbs were short (just 25 percent of the dinosaur’s entire body length). 

The Spinosarus’ tail was deep and narrow. It had a paddle-like appearance similar to the tail of crocodilians or amphibian newts. 

Habitat and Distribution

Spinosaurus lived during the Cretaceous Period, specifically in parts of present-day North Africa. 

Fossil remains have been found in Egypt, Morocco, Algeria, and Tunisia, suggesting it had a relatively wide geographic range within this region. 

During Spinosaurus’ existence, the entire African continent was part of an ancient supercontinent known as Gondwana. 

Although North Africa today has an arid climate, the region was once characterized by an extensive system of rivers, swamps, and lagoons. 

The region where the Spinosaurus lived was part of a larger coastal plain with a warm and humid climate due to its proximity to the equator.

The Cretaceous climate was generally warmer than it is today, with high levels of rainfall and seasonal weather patterns.

Spinosaurus
Spinosaurus | Elenarts108 via Getty Images

The presence of extensive river systems suggests that the Spinosaurus lived in a wet and marshy landscape.

This type of environment would have provided ideal conditions, as it was adapted for a semi-aquatic lifestyle. 

Its streamlined body, paddle-like tail, large fin-like sail, and possibly webbed feet are all adaptations that suggest an aquatic or semi-aquatic lifestyle of this dinosaur. 

The Spinosaurus’ nostrils were also positioned high up its snout compared to the nostrils of typical terrestrial dinosaurs. 

This would have allowed the dinosaur to breathe even when most of its snout was submerged underwater. 

Behavior and Diet

Spinosaurus
Spinosaurus | Warpaintcobra via Getty Images

Spinosaurus was likely capable of terrestrial locomotion but may have spent more time in the water.

The foot morphology of this dinosaur is similar to that of modern shorebirds, which suggests that its feet were adapted to walking on unstable substrates in near-shore environments.

On land, the Spinosaurus is often depicted as a bipedal animal. 

However, recent discoveries suggest that it was quadrupedal rather than bipedal. 

It was also a proficient swimmer. 

Its long, slender hindlimbs and relatively short forelimbs, combined with its elongated body, suggest it was well-suited for movement in the water. 

The Spinosaurus also had dense bones similar to aquatic creatures like manatees. 

The dinosaur’s bones may have acted as a sort of weight that helped them dive into the water to hunt for fish.

Spinosaurus moved in water by propelling its body with its tail. 

Spinosaurus
Spinosaurus | Orla via Getty Images

This is similar to the swimming motion of modern crocodiles. 

The social behavior of the Spinosaurus is still not well-understood, but predators the size of it often live a solitary lifestyle. 

It is possible that it exhibited some form of territorial behavior or competed for resources with other carnivores in their ecosystem. 

Based on speculations that it was a semi-aquatic dinosaur, Spinosaurus is often considered a piscivorous dinosaur, meaning its diet primarily comprised fish. 

The elongated snout and interlocking conical teeth of this dinosaur were similar to that of crocodilians. 

They were well-adapted to catching and holding on to slippery prey like fish. 

Spinosaurus likely relied on its sharp teeth to grasp and impale fish, while its long, narrow jaws may have helped it snatch prey from the water’s surface. 

In addition to fish, it may have opportunistically consumed other small to medium-sized prey such as turtles, crocodilians, and smaller dinosaurs. 

Spinosaurus
S. aegyptiacus head based on the 2005 reconstruction by Cristiano Dal Sasso | Steveoc 86 via Wikipedia (CC BY 2.5)

However, the evidence for such dietary variety is still limited. 

Fossils of Baryonyx, a relative of the Spinosaurus, have been found with fish scales and bones of a juvenile iguanodon in its gut. 

Scientists have also found a pterosaur bone with a spinosaur tooth embedded in it, suggesting that the spinosaurs may have occasionally preyed on flying reptiles. 

Given its size and strength, it is also possible that Spinosaurus engaged in scavenging, taking advantage of carrion when available.

It probably used various hunting strategies to obtain food. 

This may have included patrolling riverbanks, wading through shallow waters, or even swimming actively in pursuit of fish.

Its ability to move efficiently in both terrestrial and aquatic environments would have provided it with a wide range of hunting opportunities.

Life Cycle

Spinosaurus
Cast of FSAC-KK-11888, currently classified as Spinosaurus, displayed in a swimming posture at the Field Museum of Natural History in Chicago, Illinois. | 3blindMies via Wikipedia (CC BY-SA 4.0)

Due to the scarcity of fossil remains, our knowledge of the reproduction and life cycle of the Spinosaurus is limited. 

Like other dinosaurs, it most likely reproduced sexually. 

Male and female Spinosaurus individuals would have engaged in courtship behaviors to attract mates and form breeding pairs. 

Modern animals with elaborate body structures often use them for display purposes to attract mates. 

The sail of the Spinosaurus may have served a similar purpose too. It was probably brightly colored and varied in size between males and females. 

Spinosaurus
Spinosaurus | Racksuz via Getty Images

Spinosaurus females probably laid eggs after mating. 

While no nests have been found so far, experts think they laid eggs on land. It isn’t certain if the parents guarded their egg nests till they hatched. 

The hatchlings would have been relatively small, but experts think they developed their semi-aquatic adaptations very young. 

A specimen of a juvenile Spinosaurus found in 1999 shows signs that the individual was either semi-aquatic at birth or developed that lifestyle at a very young age. 

Evolution and History

Spinosaurus
Illustration of an adult and a young Spinosaurus | XiaImages via Getty Images

Spinosaurus belongs to a large group of dinosaurs known as theropods, which includes other iconic carnivores like the Tyrannosaurus rex and Velociraptor

Within the theropod lineage, it is classified into a subgroup called the spinosaurids.

Spinosaurids were quite widespread during the Late Cretaceous Period, between 130 and 95 million years ago. 

But the oldest known member of this family evolved during the Middle Jurassic Period.  

Spinosaurus
Spinosaurus | Kitti Kahotong via Getty Images

Although not directly related to the crocodilians, Spinosaurus and its other relatives show many converging evolutionary traits with them. 

Early crocodilians had skulls similar to that of theropods

Older spinosaurids like the Baryonyx were largely terrestrial but capable of swimming. 

Over time, changes in the North African ecosystem may have forced later species like the Spinosaurus to adapt to a more aquatic lifestyle in search of food. 

Experts think these changes in their skull morphology were caused by changes in their diet from consuming terrestrial prey to eating fish.

Interactions With Other Species

Spinosaurus
Restoration of Spinosaurus with contemporaneous animals of the Bahariya Formation | Andrew McAfee – Salem, Belal S. via Royal Society Open Science

As one of the largest predators around, Spinosaurus likely had few natural enemies in its ecosystem that may have posed a threat. 

The large size of this carnivore would have given it a formidable presence that discouraged any enemy from attacking. 

Scientists also think the Spinosaurus’ sail may have served as a warning signal to intruders in its territory. 

Similar to the dorsal fin of sharks, the sight of the its sail jutting out of the water would have been enough to warm off intruders. 

Gage Beasley's Spinosaurus  Green Plush Toy
Gage Beasley’s Spinosaurus Green Plush Toy

However, juvenile or injured Spinosaurus individuals could have been vulnerable to predation by larger theropods or other carnivorous dinosaurs such as Carcharodontosaurus, Deltadromeus, and Bahariasaurus that lived on the tidal flats and mangrove forests of North Africa during the Late Cretaceous. 

Although competition over prey and territory may have occurred between these large dinosaur species, niche partitioning would have limited encounters between them. 

Spinosaurus primarily preyed on fish but may have also targeted other small to medium-sized aquatic or semi-aquatic prey, such as turtles or smaller dinosaurs that ventured near the water’s edge.

Cultural Significance

Spinosaurus
Spinosaurus | Warpaintcobra via Getty Images

With its massive size, unusual neural spine, and fearsome crocodile-like jaws, the Spinosaurus is a well-known dinosaur to fans and enthusiasts. 

The distinct appearance of this dinosaur is the reason why it is so popular. 

Reference is often made to the fact that it’s the largest known carnivore, beating the equally massive and iconic Tyrannnosaurus rex

Spinosaurus has been featured in the famous Jurassic Park movies.

In the 2001 installment of the film “Jurassic Park III,” the dinosaur appeared in a scene where it faced off against the famous T-Rex. 

While an encounter between these two species would have been unlikely in real life (due to differences in their location and when they lived), the movie’s producers set up an iconic battle between these two, with the Spinosaurus emerging as the victor. 

The Spinosaurus from the third movie returned in the fourth season of “Jurassic World: Camp Cretaceous.”

Spinosaurus
Spinosaurus from Jurassic World: Camp Cretaceous | Photo via Jurassic Park Wiki

Spinosaurus has also been featured in other dinosaur books and documentaries like Planet Dinosaur, Monsters Resurrected, and Bizarre Dinosaurs. 

Dinosaur-themed video games like Primal Carnage also feature it as one of the in-game characters. 

Despite the popularity of this dinosaur, very little is known about it in real life. 

As recent discoveries show, many of this dinosaur’s early depictions and reconstructions were inaccurate. 

So far, only about seven incomplete fossils of this dinosaur have been recovered. 

One of the best fossils of this dinosaur which was found in 1912, was destroyed during the Second World War. 

All we have left are notes, sketches, and a few photographic records taken shortly after the dinosaur’s initial discovery. 

The lack of complete fossils has left a huge gap in the scientific record regarding this dinosaur.  

Conclusion

Spinosaurus was an enormous aquatic or semi-aquatic dinosaur that lived in North Africa during the Late Cretaceous Period. 

It is one of the largest known carnivores to have ever walked the planet, rivaling large theropods like Giganotosaurus and Tyrannosaurus

The dinosaur shows several adaptations to an aquatic lifestyle, including a streamlined body, webbed feet, and paddle-like tails for swimming. 

The crocodile-like jaws of this dinosaur also suggest that it was a piscivore that thrived on hunting fish. 

Spinosaurus may have prowled the water edges or even swam actively to hunt fish. The dinosaur’s diet possibly included turtles, reptiles, and other dinosaurs. 

Due to limited fossil remains, there are still a lot of gaps in Spinosaurus research, despite being discovered more than 100 years ago. 

Our understanding of this dinosaur has changed over the years. 

As new facts emerge, we can expect even more changes in what we know about this iconic dinosaur and how it lived. 

FAQs

How did Spinosaurus get its name?

The name “Spinosaurus” is derived from Latin, combining “spina,” meaning “spine,” and “saurus,” meaning “lizard.” 

It refers to the dinosaur’s distinctive sail-like structure formed by elongated neural spines on its back.

Why did Spinosaurus go extinct?

The exact reasons for the Spinosaurus’ extinction have yet to be fully understood. 

Still, it is likely that a combination of factors, such as climate change and a decline in food availability, led to this genus’s disappearance.

Sources:

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