Ever the topic of discussion among scientists and enthusiasts alike – Spinosaurus has brought a lot of attention to itself over the last few years.
Meaning of name: Spined Lizard
Species: Spinosaurus aegyptiacus, Spinosaurus moroccansus.
Classification: Saurischia, Theropoda, Tetanurae, Spinosauria, Spinosauridae.
Size: 12-17 meters (39-56 feet).
Weight: 7-20 metric tonnes (7.7-23 imperial tons)
Time: Albian to Cenomanian stages of the Cretaceous.
Location: Morroco, Egypt, Lybia, possibly Niger.
Named by: Ernst Freiherr Stromer, in 1915 (the individual species were described in 1996 by Dale Alan Russel).
Spinosaurus, along with many other dinosaurs, has been the topic of heated discussion since it’s original discovery in 1915… a discussion which only became more heated by a controversial redesign in 2014.
It’s easy for a child to think of Spinosaurus as a marine animal, thinking of the sail as more of a fin, and this may have been the case. We don’t really know what Spinosaurus’ sail was really for, theories abound: some say the extended vertebrae supported a large lump of fat, allowing the dinosaur to survive the dry months; others say the sail was thin, as is often depicted, but that it was used to maintain temperature; while some say the sail served as a display, to frighten off rivals and other carnivores or to court a potential mate. There is no evidence that these spines supported fat or that they were used for temperature control (there aren’t deep ruts for large veins to run through), so it would seem that of the three theories, the third is the most likely.
But why would something as tall as, and even longer than, a Tyrannosaurus need to look bigger? This is where the 2014 redesign comes in.
In 2014, palaeontologists pooled together everything we know about Spinosaurus, along with every single Spinosaurus fossil they could get their hands on. And the results are fascinating. I found a picture showing the skeletal structure of the reconstruction, this reconstruction is just as hated by dinosaur enthusiasts now as the move from giant iguana to Iguanodon was back when palaeontology was still finding it’s place in the world.
The fossils used in the reconstruction came from many different individuals of the genus, some argue that the fossils represented Spinosaurs of differing ages and sexes, with some even saying fossils from aegypticiacus and moroccansus were mixed. The mixing of species allegation was completely false, allegations of differing ages and sexes were true but the age differences were so small they were negligable and there appear to be no physical differences between sexes anyway.
The latest reconstruction has Spinosaurus down on all fours, only being capable of slow movement on two very short hind legs. The sail has been flattened a little and Spinosaurus has now been made a mostly aquatic dinosaur.
Whichever design you prefer, the latest theory is treated as fact until sufficiently disproven, so this is the Spinosaurus the next generation will grow up with.
This has been Spinosaurus, this has been me, and you’ve been reading Palaeontology Made Easy.
Image credits go to National Geographic.