May 23 - CT scanning is giving scientists an unprecedented look at pliosaurs, the dominant marine reptile of the Jurassic era. University of Bristol researcher Davide Foffa collated 2,000 individual scans of a fossilised pliosaur's skull and discovered that its snout contained an intricate nerve system similar to that found in crocodiles. Jim Drury reports.
The fish-eating pliosaur was the dominant marine reptile of the Upper Jurassic era 200 million years ago. Until now, little was known of its biology, but a team led by University of Bristol researcher Davide Foffa, has made some startling discoveries. The researchers collated 2,000 individual CT scans from a fossilised pliosaur skull found five years ago. SOUNDBITE (English) DAVIDE FOFFA, RESEARCHER AT UNIVERSITY OF BRISTOL, SAYING: "While looking at the CT scans we found that there were some branches and unusual channels that we never noticed before, so we thought it was a good idea to follow them and trace them digitally, and at the end we discovered these extensive neurovascular web of channels." The channels probably housed the maxillary artery and trigeminal nerve, which carried signals to and from the upper jaw and snout. Foffa thinks they may have supplied blood and nerve connections to skin and soft tissue in the snout. This would have helped pliosaurs hunt prey and manipulate food in the water, like a modern-day crocodile. SOUNDBITE (English) DAVIDE FOFFA, RESEARCHER AT UNIVERSITY OF BRISTOL, SAYING: "We found that this kind of system we found in the snout could be linked to prey detection, in a way similar as crocodiles do. In crocodiles the trigeminal nerve goes to some receptor in the snout, which help them (in) detecting movement of preys." Palaeontologists have long thought pliosaur skulls contained small holes called foramina that lead to internal channels, but this is the first concrete evidence of it. The pliosaur was around eight metres in length, with a large, crocodile-like head, a short neck, and whale-like body. Four powerful flippers helped propel it through water while its large jaws, containing teeth the size of cucumbers, seized and crushed prey. It's believed the larger pliosaurs could have swallowed a cow in a single bite. CT scanning involves using X-rays to make detailed pictures of structures inside the body. It's helping paleantologists everywhere uncover the secrets of prehistoric lifeforms in unprecedented detail, while leaving fossils undamaged and intact.