Home/Dinosaur Fans, everything Dinosaur News and Updates, key Page/Why walk Spinosaurus have a Sail top top its Back?
Theories ~ above Spinosaurus – the Sail-back Dinosaur

Spinosaurus was among the many spectacular spring meat-eating dinosaurs. Like many of the huge carnivores, fossils that this bizarre pet are very rare. As pets move increase the food chain, your numbers end up being smaller and they make up an ever decreasing ratio of the ecosystem, which method it is much less likely for any of them come be kept as fossils. For example, researchers in Canada and the western unified States can conduct researches on duck-billed dinosaurs (herbivores) that involve numerous skeletons, however in contrast there are only around 30 known fossils of Tyrannosaurus rex.

You are watching: Dinosaur with a big fin on its back

Spinosaurus is also less well-known, this is since a number determinants have conspired come leave united state with tiny fossil evidence of this dinosaur. Over there are couple of Spinosaurus continues to be partly because as a meat-eater and also at the height of the food chain there were fewer that them approximately at any kind of one time and additionally because the area of Africa that Spinosaurus lived in during the Cretaceous has actually still come be fully explored. Unfortunately, the 20th Century has been specifically unkind to this dinosaur, through the finest fossils of Spinosaurus being damaged in a bombing raid over Germany throughout WWII.

Ernst Stromer von Reichenbach, a German palaeontologist and geologist uncovered the first fossils the Spinosaurus (1912), in an area about 300 kilometer south-west of Cairo, Egypt. A number of German funded and led expeditions were despatched to phibìc Africa in between 1911 and 1914, Spinosaurus was named and also described by serious Stromer von Reichenbach in 1915. Estimates of its size vary, with most scientists stating the these animals grew come lengths in overfill of 12 metres and also they may have weighed as lot as 4 tonnes.

An Illustration of Spinosaurus (S. Aegyptiacus)


A drawing of Spinosaurus

Picture Credit: everything Dinosaur

Over the critical ten years or so much more partial stays of Spinosaurs have actually been found. There are now believed to have actually been two varieties of Spinosaurus around during the mid Cretaceous (approximately 95 million year ago). The larger varieties S. Aegyptiacus from Egypt and also a much less well known, smaller varieties from Morocco (S. Marocannus), which was named and described in 1996. Spinosaurus marocannus has yet to be universally accepted as a various species, the is tho classified together “Nomen dubium” – a name given to an animal whose validity is tho in doubt.

In 2005, Cristiano Dal Sasso and also his partner at the public Natural background museum in Milan, Italy, brought out a research of the partial stays of a Spinosaurus skull that had been uncovered just a couple of years earlier. The presumption had always been that the initial Spinosaurus discovered in 1912 was a sub-adult and not fully grown. Using those components of the skull the they had actually – greatly parts that developed the top jaw, this team of researchers calculated skull length and from this castle deduced the in its entirety size of this particular specimen. They concluded the the skull would have exceeded 1.75 metres in length, making it similar to the dimension of the best Tyrannosaur or Allosauroid skulls known.

They concluded the this creature would have actually been in between 16 – 18 metres lengthy (approaching 60 feet in length) and also would have weighed as much as 9 tonnes. Spinosaurus might lay claim to the title of the biggest meat-eating dinosaur known.

A dimension Comparison between Spinosaurus aegyptiacus and Tyrannosaurus rex


Comparing T. Rex to Spinosaurus

Picture Credit: whatever Dinosaur

The above diagram do the efforts to to compare the projected sizes of T. Rex and also the largest known species of Spinosaurus. Scientists are tho unsure exactly how much Spinosaurus weighed. It might not have been as heavy as Tyrannosaurus rex yet if the Italian led team from the civic Natural background museum that Milan space correct, the biggest Spinosaurs would have been much longer than the biggest known T. Rex. The figure of a man (approximately 1.80 metres tall) is given to administer further scale.

The many striking feature about Spinosaurus was certainly its large sail. Again estimates vary as to the size of the sail, but most scientists agree that at that is highest point it was between 1.5 to 2 metres tall. Very few fossils of these spines (called neural spines) have actually been collected. Because that example, in the initial 1912 specimen just 8 elements of separation, personal, instance neural spines space known, most of which to be not discovered in association v the back vertebrae. The German scientists had actually no actual idea how these spines fitted along with the backbone, or indeed which order they must be put in. The picture of the team’s make the efforts to reconstruct the backbone display the spines i ordered it in a nice convex pattern, however the vertebrae associated to the spines for the restoration are clearly in the not correct order.

The spines themselves seem to have a expanded out height end, they are sort the spoon shaped or spatula like. Comparable shaped neural spines deserve to be uncovered in bison, this spines help support a fleshy lump on the backs that these animals where fat is stored to help the pets through leaner times.

One of the original Photographs of the skeleton making up part of the “Sail” that Spinosaurus


A photo of those expanded neural processes

Picture Credit: Washington college in St. Louis

The photo shows the German team’s make the efforts to reconstruct the sail the the Spinosaurus remains found in 1912. The case in the bottom appropriate of the snapshot displays the conical this of Spinosaurus uncovered with this fossil bones. Underneath the teeth is the pointer of the reduced jaw (Dentary) the was likewise found.

This is the just photographic evidence of ernst Stromer von Reichenbach’s work-related on the Spinosaurus fossils, all the various other photographs were destroyed by the Allied battle raid on Munich in 1944.

A variety of theories about the sail have actually been put forward. It has been argued that such a large animal might use the structure on its back like a sail ~ above a delivery to help it move or at least keep steady as the lumbered along. A similar theory was put forward countless years back concerning the function of the sail ~ above the back of a mammal-like reptile called Edaphosaurus.

It is believed that Spinosaurus to be a fish eater. There is no proof because that this, the eight of Spinosaurus have actually never to be found however as the jaws are similar to Baryonyx (a relative, i beg your pardon scientists believe did eat fish), possibly the sail was offered to actors a shadow end water to tempt fish or come let Spinosaurus check out fish in the water there is no the reflection from the water surface ar to distract it.

Could the sail have actually acted as a device for helping Spinosaurus warmth up conveniently in the beginning and also end the the day, as well as helping to store it cool under the mid-day sun? Palaeontologist believe that the sail area to be well supplied with blood vessels, transforming to face the sun in the morning would have actually helped this pet to warmth up quickly, perhaps offering it an advantage over the other meat-eaters the roamed north Africa at this time. Turning directly right into the sunlight at mid-day would have actually exposed just a small section of the sail’s surface ar area to the sun and this would have actually helped Spinosaurus save cool.

Another theory has been put forward recently by a young dinosaur fan referred to as Ewan. He thinks that the sail top top the back of Spinosaurus might be a mock spine, that might put off an attack dinosaur. We know that Spinosaurus mutual its civilization with some very ferocious carnivores such together Carcharodontosaurus, the spine might make Spinosaurus look at bigger than it in reality was for this reason it can intimidate predators. We know from bite clues on Hadrosaurs the the back was a favourite area come target for the large meat-eaters, probably the spine helped safeguard the vulnerable earlier and neck of Spinosaurus. Many animals use spines together a type of defence, so why no a Spinosaurus. The is absolutely an exciting theory and also without much more fossil evidence like the other theories concerning the sail top top a Spinosaurus the cannot easily be disproved.

See more: Why Do You Say Bless You When Someone Sneezes ? Does Your Heart Stop When You Sneeze

Our own favourite theory involves a theory placed forward recently from palaeontologists that studied the staying Spinosaurus fossils as well as the drawings made by the German team under the supervision of ernst Stromer von Reichenbach. Fortunately, many of these drawing survived the war and also they aided to offer today’s scientists a distinctive insight into just how flexible the backbone of Spinosaurus was. Indigenous the fragmentary remains and also the beautiful pencil and also ink drawings from the critical century, scientists have actually calculated the the backbone was fairly flexible. Probably Spinosaurus had the ability to flex its back and spread out the sail prefer an massive fan. If the sail had actually been brightly coloured it might have been offered to attract a friend or to scare turn off rivals. As result of recent research studies of Theropod mind cases and other evidence amassed from research studies of the skulls and also in the specific the area wherein the optic nerve to be present, it is currently thought the these dinosaurs had great eye-sight and also colour vision, so a big, colourful signalling device would have actually been extremely useful.