Temporal range: Early–Late Cretaceous
|An artist's illustration of Spinosaurus aegyptiacus|
Stromer et al., 1915
| †'Spinosaurus aegyptiacus|
Spinosaurus is known from several poor specimens. The holotype specimen was discovered in 1915 in Egypt, by German paleontologist Ernst Stromer. The specimen included the lower jaw, teeth, several neural spines, ribs, vertebrae and a single phalanx.
Stromer measured the maximum length of Spinosaurus as 12 meters (40 ft), despite the holotype measuring only about 10 meters (33 ft) long. Sadly, the holotype specimen was destroyed after the museum, where the fossils were displayed at, was destroyed by Allied forces during the night of 24/25 April 1944.
Newer discoveries from Tunisia in 1999 and Morocco in 2005 and 2014 suggest that Spinosaurus may have reached 18 metres (59 ft) in length. A size estimate by Dr. Dal Sasso suggests that the animal could have reached a length of 20 metres (66 ft) in length, however this claim may be an over-estimation.
The largest known specimen was found by Spanish palaeontologist Cristiano Dal Sasso, in Morocco in 2005. The specimen includes a near complete upper jaw which measures about 2 metres (6 ft) long, with a small amount of well preserved teeth. The latest finds, also discovered in Morocco, were discovered by Dr. Nizar Ibrahim and Dr. Paul Sereno. The specimen includes well preserved hind limbs, four neural spines, gastralia and some parts of the skull from the postorbital area.
Ibrahim and Sereno made a new reconstruction of this animal, suggesting that Spinosaurus may have had a quadrupedal posture. However, this reconstruction has been criticized by both the public and the scientific community, although some people and scientist support it, some people (including scientists) believed it to be a chimera or error by Ibrahim due to an error in the original paper's description of how the measurements were done. Including Scott Hartman & John Hutchinson. A new revision has been published which has proved supporting Ibrahim's measurements.
It is unclear whether one or two species are represented in the described fossils. The best known species is Spinosaurus aegyptiacus from Egypt, although a potential second species named Spinosaurus maroccanus (which is currently considered to be a junior\nomen dubium) has been discovered in Morocco in recent times but it is not officially recognized by this name.
Due to the body shape and limb orientation it's bio-mechanics are more comparable to an aquatic bird like a cormorant or pelican rather than a crocodile. Spinosaurus is thought to have been semi-aquatic due to its diminutive limbs, but no one knows for certain how spinosaurus would have moved when on land. Plausible theories include walking on its splayed finger tips, on its forearms, or leaning backwards in a penguin\pangolin\pelican like posture.
This diagram shows possible methods of land based locomotion for spinosaurus:
Two species of Spinosaurus have been named: Spinosaurus aegyptiacus (meaning "Egyptian spine lizard") and Spinosaurus maroccanus (meaning "Moroccan spine lizard")
The first described remains of Spinosaurus were found and described in the early 20th century. In 1912, Richard
Markgraf discovered a partial skeleton of a dinosaur in the Bahariya Formation of western Egypt. In 1915, German paleontologist Ernst Stromer published an article assigning the specimen to a new genus and species Spinosaurus aegyptiacus.
Fragmentary additional remains from Bahariya, including vertebrae and hindlimb bones, were designated by Stromer as "Spinosaurus B" in 1934.Stromer originally believed they belonged to juvenile Spinosaurus, but after closer research and bone analysis, he determined that specimen was actually a chimaera, with remains of Sigilmassasaurus and Carcharodontosaurus.
We don't have complete Spinosaurus' skeletons, but we have some of his parts of body. We have about 8 ft long jaws, formed to grabbing and neural spines, that maybe created the sail. However, newest reconstruction by Dr. Nizar Ibrahim shows that neural spines had shape similar to bison's. That may indicate Spinosaurus
actually had some kind of hump, not a sail. But, we have near complete skeletons of his cousins, Baryonyx and Suchomimus. They were just smaller versions of Spinosaurus, without a sail. So we can easily reconstruct the Spinosaurus based on mentioned dinosaurs.
S. maroccanus was originally described by Dale Russell in 1996 as a new species based on the length of its neck vertebrae. Specifically, Russell claimed that the ratio of the length of the centrum (body of vertebra) to the height of the posterior articular facet was 1.1 in S. aegyptiacus and 1.5 in S. maroccanus. Later authors have been split on this topic. Some authors note that the length of the vertebrae can vary from individual to individual, that the holotype specimen was destroyed and thus cannot be compared directly with the S. maroccanus specimen, and that it is unknown which cervical vertebrae the S. maroccanus specimens represent. Therefore, though some have retained the species as valid without much comment, most researchers regard S. maroccanus as a nomen dubium or as a junior synonym of S. aegyptiacus.
The animal was semi-aquatic. Spinosaurus was estimated to grow around 18 meters long, and weigh around 15 to 20 tons.
It got its name, which means "spine lizard," because of the tall spines on its vertebrae (bones of the spine), some reaching a height of six feet! They formed a sail along the animal's back, though not like those of the Permian mammal-like reptile Dimetrodon or Ouranosaurus, the hadrosaur that lived in the same time period and area, and may have been a prey item of Spinosaurus.
The enlarged vertebrae of Spinosaurus that give it its name have been a cause of a great deal of controversy in recent years, with some people claiming they were a shrink wrapped sail akin to Dimetrodon or Edaphosaurus, and others arguing instead that it was a thick ridge or hump akin to a bison or rhinoceros. The remains published in 2014 have shown that the vertebral spines narrow at the top nearer the front end of the animal, which means they would not have supported a thick fatty hump, however they still do not display the characteristics of a “true sail-back” either. There were "few channels for blood vessels" meaning it likely wasn't for thermal regulation. Sail-backed reptiles have supports for their sails that are thin, almost like the rays of a fishes fins, this can be seen for example in modern basilisks, whereas the vertebra of Spinosaurus are thick at the base and narrow towards the top. In life the structure would have appeared rising from the body to form a triangular shape over the animals back (when viewed from in front), as opposed to either a shrink wrapped sail or a large hump, it would have been most akin to chameleons. However, the vertebrae towards the animals hips were thicker, and could have supported a hump, perhaps to aid in buoyancy or balance.
Spinosaurus' primary weapon are its mighty 7 foot arms with 25-30cm fingers armed with 15-20cm claws, designed for killing and occasionally for walking. The arm would swipe at another predator causing the claws to dig extremely deep into the flesh while the fingers are just an extension, like a knife has a handle, making the claw go deeper into the prey or competitor. Then, secondary weapon are its specialized 5.5 foot jaws. These jaws are formed for the grabbing the prey, clamping down and suffocating it and they are most similar to these of crocodile. So, scientists guess that it used them like a crocodile, to throw prey from side to side. Brutally torn the prey into smaller 'pieces'. The jaws also had conical teeth like today's crocodiles. The teeth were hollow, designed for fish hunting meaning it had a relatively weak bite compared to other predators but is able to kill all the same.
Spinosaurus a semi-aquatic animal. Proof of this is the elongated feet, hydrodynamic design and sensors in the form of small holes, on the top of its snout. They were perfect for locating fish in the water. This was found when in 2010 an isotope analysis by Romain Amiot and colleagues found that oxygen isotope ratios of spinosaurirud teeth, including teeth of Spinosaurus, indicate semiaquatic lifestyles. Spinosaurus snout was narrow like a dolphin or gharial, and it would not have been good at crushing or tearing prey like crocodiles or alligators.
Isotope ratios from tooth enamel and from other parts of Spinosaurus and of other predators from the same area such as Carcharodontosaurus were compared with isotopic compositions from contemporaneous theropods, turtles, and crocodilians.
The study found that Spinosaurus teeth from five of six sampled localities had oxygen isotope ratios closer to those of turtles and crocodilians when compared with other theropod teeth from the same localities. The authors postulated that Spinosaurus Switched its living/hunting Territory between terrestrial and aquatic habitats to compete for food with large crocodilians and other large theropods. This is strongly suggest The Spinosaurus has more Amphibious (Lives Between Both Land and Both Water) lifestyle rather than a Fully Aquatic lifestyle.The teeth are different from other theropod teeth because they were conical and the serrations (the cutting ridges along the sides) were very small. These tooth features, along with the shape of the skull bones, show that Spinosaurus is similar to Baryonyx and Suchomimus. They are both part of the group spinosauridae, but Spinosaurus belongs to a sub-group known as spinosauridae, while Baryonyx belongs to a separategroup known as baryonychidae, which have different features among their members.
Spinosaurus is believed to have eaten fish, but there has been controversy about a dinosaur of that sizerelying on just fish, no matter how big the fish were. Spinosaurus ate large fish, but in times of famine and drought which were common it would scavenge and hunt small-sized prey to large prey (Ouranosaurus). Its also possible Spinosaurus used its size and Claws to scare off other Carnivores (like Carcharodontosaurus and Sarcosuchus) and eat/scavenge their kill much like Short-Faced Bears of ice Age.In 2014, paleontologists Paul Sereno and Nizar Ibrahim discovered that Spinosaurus' vertebrae actually had a dip in the sail and its legs were much shorter than previously thought. This has brought the suspicion that Spinosaurus was likely more aquatic than previously thought, spending nearly all of its time in the water, and almost all its entire diet was piscivorous based. Its shorter legs have also made scientists wonder if part of the time Spinosaurus was semi-quadrupedal instead of bipedal like most theropods. However, this thesis was very criticised among the scientific community, because the specimen is possibly a chimaera (Hutchinson et al.) or a juvenile (Hartman et al.) (Chimaera meaning some parts were from another individual). Dr. Scott Hartman says that dinosaurs are able to change during their growing process extremely (Horner et al.). The best example of changing during growing process is small ornitischian dinosaur, called Dryosaurus. Dryosaurus juveniles had very large and muscular forelimbs, what indicates they have locomoted on all fours. As they grew, their forelimbs became smaller and more useless, until they become absolutely bipedal animals in adult stage. So, this might be the case with Spinosaurus, too. Also, Hartman says that there's no need for such a disorder. Recent studies have determined that all Spinosaurids were amphibious animals, but still, they were bipedal animals.
The original first skeleton of this theropod was destroyed during the course of World War II. However, a piece of a skull bone belonging to another Spinosaurus that was found on a shelf in a German museum. It is most likely that another expedition to Egypt would uncover more skeletons so that more can be learned about Spinosaurus. It also lived with sauropods like Paralititan, other large carnivores like Carcharodontosaurus and Sauroniops, and large crocodiles like Sarcosuchus.
In the Media
Spinosaurus has become an iconic dinosaur and its famous for the highly popular dinosaur movie: Jurassic Park ///, the first Jurassic Park film not based on a Michael Crichton book. Spinosaurus was portrayed as the main "villain" that caused destruction in its path. In an infamous scene, this Spinosaurus was seen fighting a Tyrannosaurus rex and defeating it. Spinosaurus also appears in most of the jurassic park expanded universe, including games and toy lines.
Spinosaurus appears in the video game Carnivores 2, with an inaccurate anatomy because in the epoch there was little information about this dinosaur.
Spinosaurus appears in series 4 of Primeval and is shown living in the same place as a Raptor (Dromaeosaur). Another one appears in Series 5.
Spinosaurus is also in Monsters Resurrected, portrayed as the "Biggest Killer Dino", where it was inaccurately shown to be thesuper top predator on land. It was seen lifting up a Rugops, kill a Carcharodontosaurus with a single slash of its claws, and slice up the sides of Sarcosuchus. The portrayal was noticeably over-powered compared to the real dinosaur
A Spinosaurus, nicknamed "Spike", makes an appearance in the video game Jurassic: The Hunted, appears as a boss.
Spinosaurus appears in Bizarre Dinosaurs, where its sail is talked about.
Spinosaurus appears in the Japanese animated film Doraemon: Nobita's Dinosaur 2006, where it is the abused pet of an evil time-travelling dinosaur poacher. Also, near the climax, Spinosaurus faces off with Tyrannosaurus.Spinosaurus appears in the first episode of Planet Dinosaur as a fish hunter and shown to hunt land animals if there is no aquatic animals to eat (no animal eats one thing being a opportunist spinosaurus would likely eat whatever it could), and competes against a Carcharodontosaurus for an Ouranosaurus carcass and defeats it in battle with its claws. It also is a playable character in Primal Carnage.
Spinosaurus also appears in the 12th episode of The Land Before Time, but is inaccurately shown with only two fingers.
A Spinosaurus makes a brief appearance in the Asylum film Age of Dinosaurs where it somehow is able to climb on top of a tall building.
In Fossil Fighters series, Spinosaurus is a playable vivosaur.
Spinosaurus was the main character in Ricardo Delgado's Age of Reptiles: Ancient Egyptians mini-series.