A University of Alberta-led research team has taken a rare look inside the skull of a dinosaur and come away with unprecedented details on the brain and nasal passages of the ancient animal.
Lead researcher Tetsuto Miyashita, a U of A masters student in paleontology, examined the armoured skull of a 72-million-year-old Euoplocephalus.
“The skull had been sitting in the U of A’s paleontology collection for about 30 years when I found it,” said Miyashita. “The skull was broken, but through the opening we got a unique view of the interior nasal cavities and details of blood vessels.”
Euoplocephalus was a six-metre-long plant eater that lived in what is now Alberta and Montana. Prior to Miyashita’s discovery of the broken-skull specimen, researchers hadn’t been able to see beneath the fused bone plates of Euoplocephalus’ heavily armoured head.
“With that fossil, we reconstructed what the brain and nasal passage looked like,” said Miyashita. The team then put together an even more detailed picture of the dinosaur’s brain cavity and interior skull by taking multiple X-ray and CT scans of three undamaged Euoplocephalus heads.
The researchers concluded that Euoplocephalus’s brain, although not small by dinosaur standards, could fit in a coffee cup. They also learned something new about what went on inside its head. “The nasal passages were long and looping, which indicates it had a good sense of smell and hearing,” said Miyashita. “The inner ear we reconstructed was long, suggesting it was tuned to pick-up low-frequency sounds like a nasal roar.
“That feature of the skull interior may have allowed it to hear another Euoplocephalus’ trumpet-like call from a great distance.”
The research paper on Euoplocephalus was written by Miyashita, U of A colleague Victoria Arbour, Lawrence Witmer from Ohio University, and was supervised by U of A biology professor Philip Currie.