It might look like a tiny rock, but it's actually dinosaur brain. (Jamie Hiscock)
National Geographic has a story about a fossil dinosaur brain. The fossil was discovered back in 2004 on a Sussex beach. It dates to the Cretaceous Period, about 133 million years ago. The brain is believed to belong to a relative of Iguanodon.
Original paper in Geological Society
Quirks & Quarks segment from October 29th, 2016
The 133-million-year-old fossil belongs to a relative of Iguanodon, an iconic herbivorous dinosaur that lived during the early Cretaceous. The fossil mostly consists of an endocast—a sediment cast of the skull cavity where the dinosaur’s brain resided.
Typically, endocasts give vital but indirect information about the brains of fossilized animals, as these sensitive organs are often the first to decay. But this endocast’s top surface contains microscopic features that appear to be directly mineralized bits of brain tissue.
Fibrous textures across the endocast surface probably started as pieces of the meninges, the tough, protective membranes that envelop and nurture the brain. Mineralized networks of blood vessels—some smaller in width than a human hair—crisscross the surface. And tantalizingly, ripples in the preserved meninges might trace some of the folds in the cortex, the wrinkled outer layer of the brain.
“That is the nearest I suspect we’re ever going to get to the whole [brain],” says paleontologist David Norman of the University of Cambridge, one of the researchers who worked on the fossil. The remarkable find was announced on October 27 at the Society of Vertebrate Paleontology’s annual meeting in Utah.