Evidence of blood vessels and nerves in the head of dinosaur fossils has generally been hard to come by. But using advanced imaging techniques, scientists have now built an unprecedented 3D picture of the interior of the skull of Neovenator salerii. They found that the carnivorous land dinosaur may have possessed a surprisingly sensitive snout that it used for foraging, feeding and even wooing potential mates.
Evidence of this type of sensitivity in a dinosaur's snout has been found previously in other species, but these have all had one thing in common: they did their hunting in the water. Neovenator salerii, by contrast, went about its business on land.
So when scientists at the University of Southampton studied the fossilized skull of a Neovenator (which means "new hunter" by the way), and found evidence of pressure receptors, blood vessels and nerves, it opened up some interesting possibilities. The team made the discovery using an imaging technique called micro-focus computed tomography, and describe what they saw as a complex network of large, laterally-situated anastomosing channels.
"The 3D picture we built up of the inside of Neovenator's skull was more detailed than any of us could have hoped for, revealing the most complete dinosaur neurovascular canal that we know of," said University of Southampton graduate Chris Barker, leader of the study. "The canal is highly branched nearest the tip of the snout. This would have housed branches of the large trigeminal nerve – which is responsible for sensation in the face – and associated blood vessels. This suggests that Neovenator had an extremely sensitive snout – a very useful adaptation, as dinosaurs used their heads for most activities."
With nothing to suggest Neovenator was an aquatic species, the scientists were left to ponder how this snout was put to use on land. Its sensitivity to touch, pressure and temperature could have proven useful for activities such as taking the temperature of a nest, carefully carrying their young in their jaws, or stroking each other's face during courtship, as well as other tasks.
"Having such a sensitive snout could have had a social use too," says Barker. "Many birds – which are the descendants of dinosaurs – use their beaks in social display, and there is plenty of evidence that carnivorous dinosaurs engaged in face-biting among themselves, perhaps targeting the sensitivity of the face to make a point."
Another interesting finding from the study was images of wear patterns on the dinosaur's teeth. The researchers say that these seem to indicate that the animal carefully avoided making contact with bones when removing flesh, another trait possibly enabled by its ultra-sensitive snout.
"Our results add a new level of detail to our understanding of the way large predatory dinosaurs interacted with the world around them," says Elis Newham, a University of Southampton PhD researcher and study co-author. "The range of exciting possibilities for such facial sensitivity show just how far we have come in our re-assessment of dinosaurs from lumbering beasts to complex, highly adapted organisms."
The research was published in the journal Scientific Reports.
Source: University of Southampton