Scientists find the first fossilized dinosaur brain - but what took so long?

Story highlights

  • Preserving soft-tissue in terrain animals is rare because they decay quickly
  • "In a way it is like recreating a forensic scene," scientist says

(CNN)A little over 130 million years ago, a plant-eating dinosaur was roaming the present-day area of Sussex, England, when -- trapped by the muds of a thick swamp -- it fell backward to his death and was forgotten.

Until today.
    Its brain -- almost dismissed as another shiny brown pebble along the British coastline -- has just been officially identified as the first preserved dinosaur brain in history.
    Dr. David Norman, a British palaeontologist from the University of Cambridge's Department of Earth, is part of the team of international researchers who analyzed the fossil found in 2004 by amateur fossil hunter Jamie Hiscocks in Surrey, England.
    For Norman, trying to understand how the dinosaur, known to science as Bexhill iguanodontian, died was key to understanding how the brain was preserved.
    "Of course, dinosaurs have brains. But this discovery is amazing, in itself,because of the rarity of preserving soft-tissue in terrain animals because they decay so quickly," he told CNN.
    An idealized reconstruction done by researchers of the head of an iguanodontian dinosaur showing the dorsal braincase and associated soft tissue feature.
    "In a way it is like recreating a forensic scene. How could the brain have been preserved? You have a dead body and you have to explain how it got there," he said.
    The researcher believes the fossil, which shows similarities to the brains of present-day crocodiles and birds, was preserved due to the dinosaur dying in a swamp-like environment which mixed low levels of oxygen -- known to slow decay -- and acidity which can preserve soft tissue for long periods.

    The size of the brain

    While the fossilized brain fits in a closed hand, its size is also raising attention as it is considered large for the herbivorous dinosaur that it belongs to.