First dinosaur brain fossil found

Fossilised dinosaur brain tissue identified for first time

The size most likely comes from the way the species died. But the recent discovery of the first recorded fossilised brain tissue could help challenge that image.

It was discovered by fossil hunter Jamie Hiscocks on a beach near Bexhill-on-Sea in 2004. The scientist thinks that fortune favored them; the theory is "that the dinosaur's brain was preserved in highly acidic water, possibly from a bog or swamp, protecting its form before the whole animal was drowned". Found among rocks laid down during the early Cretaceous Period around 133m years ago, the fossil is an endocast, formed as layers of sediment gradually filled up the skull.

As rare as this fossil tissue may be, is it possible that there are other soft-tissue fossils that have flown under the radar?

"The fossil we have nearly seems as it belonged to a mammal". They could observe where the blood vessels in the brain were. There are even hints of deeper tissues that may have formed part of the brain cortex, the functional part of the brain that contains neurons. "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".

Taken together, these observations create a picture of the dinosaur dying in a well-vegetated, swampy environment. I noticed there was something odd about the preservation, and soft tissue preservation did go through my mind.

Martin Smith, a paleontologist at the University of Durham in the United Kingdom, called the type of brain tissue preservation they found "unbelievably unlikely". Hence, they can't say for certain how large this dinosaur's brain was. This raises the likelihood that some dinosaurs had larger brains.

The researchers used special microscopes to analyze the fossilized tissue.

But the brain fossil appears to show that in Iguanodon, the protective membranes were in the region of 1mm thick. The structure of the fossilised brain, and in particular that of the meninges, shows similarities with the brains of modern-day descendants of dinosaurs, namely birds and crocodiles. However, they have stated that the brain is very similar to the ones found in dinosaurs and birds.

Further work and more specimens are needed before this finding can be confirmed.

Scientists can't say much about the nature of this dinosaur noggin - especially not how it thought or whether it was intelligent, the researcher said. Read the original article.

Alex Liu is aLecturer in Palaeobiology at the University of Cambridge.



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