Iguanodon bernissartensisWIKIMEDIA, GHEDOGHEDOAt the height of the Cretaceous Period, one hapless herbivore—likely related to Iguanodon—fell backwards into a bog, smacked its head, and addled its brain. Now, around 133 million years later, scientists have uncovered a sediment cast of that brain, etched across eons into the dinosaur’s mineralized skull. The fossil, described in a study published last week (October 27) in Earth System Evolution and Early Life, is incredibly well preserved and, according to the authors, may be the only extant impression of dinosaur brain tissue.
The endocast was first discovered in 2004, when a fossil hunter in England came across a pebble with odd ripples along its surface. Experts agreed that the pebble was a dinosaur fossil, but they hardly expected to find that it contained the mineralized remnants of soft tissue—much less the first recorded dinosaur brain. While happy accidents of rapid mineralization have indeed given us the occasional mummified dinosaur and even one ancient fish brain, fossilized dinosaur brains have remained stubbornly elusive. “Of course, dinosaurs have brains,” study coauthor David Norman, a paleontologist at the University of Cambridge, U.K., told CNN. “But this discovery is amazing, in itself, because of the rarity of preserving soft-tissue in terrain animals, because they decay so quickly.”
After examining the pebble ...
