Spinosaurs were an unusual type of carnivorous dinosaur that were aquatic as well as terrestrial (Picture: PA)
The brain of the Spinosaurus, the biggest meat-eating dinosaur that ever lived, has been unveiled by scientists.
The brain was created from the remains of two spinosaurs dug up in Surrey and on the Isle of Wight.
Scientists digitally reconstructed the dinosaur’s grey matter and inner ears from the skulls of individuals named Baryonyx and Ceratosuchops, that roamed what is now Guildford and Brightsone Bay near Sandown, respectively, 125 million years ago.
‘Despite their unusual ecology, it seems the brains and senses of these early spinosaurs retained many aspects in common with other large-bodied theropods,’ said lead author Chris Barker, a PhD student at Southampton University.
‘There is no evidence their semi-aquatic lifestyles are reflected in the way their brains are organised.’
The internal soft tissues controlled co-ordination, sight, smell, intelligence – and even reproduction.
The brain of the Spinosaurus, the biggest meat-eating dinosaur that ever lived, has been unveiled by scientists (Picture: WitmerLab/Anthony Hutchings/University of Southampton/PA)
The olfactory bulbs, which process smells, weren’t particularly developed and the ear was attuned to low frequency sounds. Those parts involved in keeping the head stable and the gaze fixed on prey were possibly less developed than in later, more specialised spinosaurs.
It suggests their ancestors already possessed brains and sensory adaptations suited for part-time fish catching. All they needed to do to become specialised for a semi-aquatic existence was evolve an unusual snout and teeth.
Spinosaurs were an unusual type of carnivorous dinosaur that were aquatic as well as terrestrial. They were equipped with long, crocodile-like jaws and six-inch razor-sharp teeth. It enabled them to stalk riverbanks for large fish.
It was a very different lifestyle to more familiar theropods such as Allosaurus and T.rex, which they dwarfed.
Baryonyx and Ceratosuchops reached 30 feet long, over 10 feet tall and weighed about five tons.
Spinosaurs were equipped with long, crocodile-like jaws and six-inch razor-sharp teeth (Picture: Sam Tonkin For Mailonline)
Ceratosuchops translates as ‘horned crocodile-faced hell heron’ – as it prowled like the wading bird. Its brow was adorned with a series of low horns and bumps.
Baryonyx refers to the animal’s very large claw on its first finger that would have ripped fish to shreds. They were powered by fin-like tails.
Soft organs, such as the brain, don’t survive fossilisation. So the British and US team used CT scans to peer into perfectly preserved cranial cavities.
They isolated sections of the skull, filling the gaps of each. Putting the regions together provided a 3D representation of the space, or endocast.
‘Because the skulls of all spinosaurs are so specialised for fish-catching, it’s surprising to see such “non-specialised” brains,’ said co-author Dr Darren Naish.
‘But the results are still significant. It’s exciting to get so much information on sensory abilities – on hearing, sense of smell, balance and so on – from British dinosaurs,’
Baryonyx and Ceratosuchops reached 30 feet long, over 10 feet tall and weighed about five tons (Picture: National Geographic)
‘Using cutting-edged technology, we basically obtained all the brain-related information we possibly could from these fossils.’
A model of Ceratosuchops’ brain is going on display alongside its bones at Dinosaur Isle Museum in Sandown.
‘This new research is just the latest in what amounts to a revolution in palaeontology due to advances in CT-based imaging of fossils,’ said co-author Professor Lawrence Witmer, of Ohio University in the US.
‘We’re now in a position to be able to assess the cognitive and sensory capabilities of extinct animals and explore how the brain evolved in behaviourally extreme dinosaurs like spinosaurs.’
Analyses has found the bones of Ceratosuchops and its cousin Baryonyx were dense, just like those of today’s penguins, hippos and alligators. This provided bouyancy, enabling them to submerge themselves to kill.
Animals that find food in water have virtually solid bones while those of land-dwellers look more like doughnuts, with hollow centres.
‘This new study highlights the significant role British fossils have in our constantly evolving, fast-moving understanding of dinosaurs,’ said co-author Dr Neil Gostling, who leads Southampton’s EvoPalaeoLab.
‘Spinosaurs themselves are one of the most controversial of all dinosaur groups. This study is a valuable addition to ongoing discussions of their biology and evolution.’
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Spinosaurs hunted in water as well as on land.
