The first fossilised dinosaur brain has been found on a beach in East Sussex and could show that the extinct giants were more intelligent than first thought.
The small brown pebble was spotted by amateur fossil hunter Jamie Hiscocks on the coastline near Bexhill-on-Sea.
It is the only piece of fossilised brain tissue from a dinosaur ever discovered and is thought to belong to a species related to the Iguanadon. It is so well preserved that even the capillaries – tiny blood vessels – can still be seen on the surface.
“The chances of preserving brain tissue are incredibly small, so the discovery of this specimen is astonishing,” said Dr Alex Liu of Cambridge University's Department of Earth Sciences which has been studying the fossil.
The structure is similar to modern-day descendants of dinosaurs - birds and crocodiles – who have sausage shaped brains which only take up about half the space of the cranial cavity.
However, the tissue in the fossilised brain appears to have been pressed directly against the skull, raising the possibility that some dinosaurs had larger brains which filled much more of the skull cap.
“As we can’t see the lobes of the brain itself, we can’t say for sure how big this dinosaur’s brain was,” said Dr David Norman.
“Of course, it’s entirely possible that dinosaurs had bigger brains than we give them credit for, but we can’t tell from this specimen alone.
“What’s truly remarkable is that conditions were just right in order to allow preservation of the brain tissue – hopefully this is the first of many such discoveries.”
The researchers say it is equally possible that the dinosaur’s brain ended up squashed against the skull casing because gravity caused it to collapse after death.
The creature to whom the brain belonged was probably a large herbivorous dinosaur that lived during the Early Cretaceous Period, about 133 million years ago.
It is though the brain tissue was essentially ‘pickled’ in a highly acidic and low-oxygen body of water – similar to a bog or swamp – shortly after its death.
“What we think happened is that this particular dinosaur died in or near a body of water, and its head ended up partially buried in the sediment at the bottom,” added Dr Norman.
“Since the water had little oxygen and was very acidic, the soft tissues of the brain were likely preserved and cast before the rest of its body was buried in the sediment.”
The team identified the tissue using a scanning electron microscope which was able to pick out the rough membranes which surround the brain, as well as collagen and blood vessels.
Mr Hiscocks, discovered the brain fragment while fossil hunting on Bexhill beach in 2004, but didn’t send it for expert examination until recently.
“I was searching by torchlight a large exposure on the foreshore that had become uncovered during a winter storm, when I spotted the fossil,” he said.
“Over the years I have developed a skill at finding fossils on the beach. It's like they jump out at me when I spot something different among the piles of rock debris.
“The specimen was lying amongst other stone debris. I noticed it had an unusual shape. I could see in my torchlight structured detail on the surface of the object, immediately I knew this wasn't any ordinary pebble or stone.
"Being such a fragile thing, the next storm could have destroyed it. Thank goodness I picked it up.”
The results are reported in a Special Publication of the Geological Society of London, published in tribute to Professor Martin Brasier of the University of Oxford, who died in 2014