AsianScientist (Nov. 3, 2016) – Researchers from Australia and the UK have found that an unassuming brown pebble found more than a decade ago is the first example of fossilized brain tissue from a dinosaur. The finding was published in a special publication of the Geological Society of London.
The fossilized brain, found in 2004 in the UK, is most likely from a species similar to Iguanodon, a large herbivorous dinosaur that lived during the Early Cretaceous Period about 133 million years ago. According to the researchers, the reason this particular piece of brain tissue has been so well-preserved is that the dinosaur’s brain was essentially pickled in a highly acidic and low-oxygen body of water, similar to a bog or swamp, shortly after its death. This allowed the soft tissues to become mineralized before they decayed away completely, so that they could be preserved.
“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,” said corresponding author Dr. David Norman from the University of Cambridge. “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.”
Dr. Dave Wacey from the University of Western Australia’s Center for Microscopy, Characterization and Analysis used scanning electron microscope techniques to identify the tough membranes, or meninges, which surround the brain, as well as strands of collagen and blood vessels. The fossil, most likely from a species closely related to Iguanodon, displays distinct similarities to the brains of modern-day crocodiles and birds.
The tissue in the fossilized brain appears to have been pressed directly against the skull, raising the possibility that some dinosaurs had large brains which filled much more of the cranial cavity. However, the researchers caution against drawing any conclusions about the intelligence of dinosaurs from this particular fossil, and say that it is most likely that during death and burial the head of this dinosaur became overturned, so that as the brain decayed, gravity caused it to collapse and become pressed against the bony roof of the cavity.
The article can be found at: Brasier et al. (2016) Remarkable Preservation of Brain Tissues in an Early Cretaceous Iguanodontian Dinosaur.
Source: University of Western Australia.
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