For 200 million years, a skull lay buried in what would eventually become rural England, more specifically, Fell Mill Farm in Warwickshire. Discovered in 1955, the three-foot-long triangular skull was in exceptional condition for something so old. Now, thanks to modern medical technology, the ichthyosaur of Warwickshire is finally getting its due.
Ichthyosaurs were giant marine reptiles that thrived from the Triassic period through the Late Cretaceous, from 250 to around 90 million years ago. While they lived in oceans across the globe, several have been found in England. But the Warwickshire skull's excellent preservation means that scientists are still learning new things about the ichthyosaur lived.
"The first time I saw this specimen I was puzzled by its excellent preservation," says paleontologist Dean Lomax from The University of Manchester, the lead author of the resulting study, in a .
"Ichthyosaurs of this age (Early Jurassic) are usually ‘pancaked’, meaning that they are squished so that the original structure of the skull is either not preserved or is distorted or damaged. So to have a skull and portions of the skeleton of an ichthyosaur of this age preserved in three dimensions, and without any surrounding rock obscuring it, is something quite special.”
While originally identified as a common species of icthyosaur, so common that it's known as Ichthyosaurus communis, Dean wasn't so sure. Using computerized tomography (CT), Dean and the team of researchers were able to properly identify it as the much rarer Protoichthyosaurus prostaxalis. The prostaxalis, only found in England, has the largest skull of any known member of its family.
“Initially, the aim of the project was to clean and conserve the skull and partially dismantle it to rebuild it more accurately, ready for redisplay at the Thinktank Museum," says coauthor Nigel Larkin, also of The University of Manchester.
"But we soon realized that the individual bones of the skull were exceptionally well preserved in three dimensions, better than in any other ichthyosaur skull we’d seen. Furthermore, that they would respond well to CT scanning, enabling us to capture their shape digitally and to see their internal details. This presented an opportunity that couldn’t be missed."
What makes the skull so fascinating to researchers is its braincase. Rarely preserved in ichthyosaurs, the braincase allows for scientists to better understand how the animals functioned. Approaching outside sources at the Royal Veterinary College in London, the skull was able to get a CT scan chiefly used for horses.
What scientists were able to find showed the dual histories of the skull—not just its history in prehistoric oceans but as an object of interest in the 1950s before modern technology had evolved to its current point.
“Scans also revealed the curation history of the specimen since its discovery in the '50s," says coauthor Dr. Laura Porro of University College London. "There were several areas reconstructed in plaster and clay, and one bone was so expertly modeled that only the scans revealed part of it was a fake."
Now, modern technology puts less pressure on the artifact by building a 3D digital re-creation of the skull, opening up study of the incredible braincase to researchers across the globe.
“It’s taken more than half a century for this ichthyosaur to be studied and described, but it has been worth the wait," says Dean. "Not only has our study revealed exciting information about the internal anatomy of the skull of this animal, but our findings will aid other paleontologists in exploring its evolutionary relationship with other ichthyosaurs.”