From: Business Insider
After being analyzed by a group of paleontologists, it was dramatically revealed to have been the fossilized soft brain tissue of an Iguanodon, a plant-eating dinosaur that lived around 133 million years ago at the start of the Cretaceous.
Significantly, this is the first ever example of fossilized brain tissue from a dinosaur. Although the original biological tissue itself no longer exists, the immaculate, complex detail of its structures have been incredibly well-preserved by what the researchers have referred to as “mineralized ghosts.”
Detailed CT scans also revealed that the fossilized remnants of strands of blood vessels, collagen networks, capillaries and even the outer layers of neural tissues were also brilliantly preserved by the natural pickling process.
Co-author Dr Alex Liu, a palaeobiologist at the University of Cambridge, told IFLScience that brain tissues “are amongst the least likely tissues we would expect to ever be found in a fossilized terrestrial vertebrate.”