Paleontologists have uncovered countless dinosaur bones, but what they have yet to find is a dinosaur brain — that is, until now. Researchers recently realized what they thought was a run-of-the-mill skull fossil actually may contain a chunk of fossilized dinosaur brain tissue. Scientists think the brain tissue came from a "large leaf-eating dinosaur, possibly from a species similar to the iguanodon," which roamed the Earth some 130 million years ago, Mashable reports.
The brain tissue, which looks like a nondescript brown rock at first glance, was found by an amateur fossil hunter in Sussex in 2004. Scientists believe the dinosaur's head fell into a swamp when it died, which prevented the brain tissue from decaying like soft tissue usually does. Instead, The Independent explained, the brain was essentially "pickled by the highly acidic and low-oxygen water."
Still, some scientists aren't convinced this is the real deal. Lawrence Witmer, a paleontologist from Ohio University, stressed that brain tissue is "one of the first things that decomposes after an animal dies." He told NPR he thinks what researchers have discovered is "part of the protective outer covering of the brain."
However, researchers insist they've spotted what appear to be blood vessels, which, Vox noted, is "the tell-tale sign this was indeed part of a brain." "They're incontrovertible, they can't be anything else," said Alexander Liu, a co-author of the research. "They have the right diameters, they branch in the right way, they're hollow, and they are in the right places."