Getting into the head of an ichthyosaur
For the first time, the ancient skull of a giant marine animal has been modelled in three dimensions. Nick Carne reports.
British researchers have recreated the metre-long skull of a giant fossil marine ichthyosaur, revealing, among a host of new information, details of the rarely preserved braincase.
It is, they say, the first time a 3D digital reconstruction of the skull and mandible of a large marine reptile has been made available for research and to the public – but it’s been a long time coming.
The almost 200-million-year-old fossil was found in a farmer's field in the English county of Warwickshire in 1955, then largely ignored.
However, in 2014, as part of a project at the Thinktank Science Museum in Birmingham, UK, palaeontologists Dean Lomax and Nigel Larkin decided to take a closer look and quickly realised they were looking at something important.
“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,” says Lomax, from the University of Manchester.
“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."
Computerised tomography (CT) scanning technology allowed them to determine just how special.
The ichthyosaur was originally identified as a common species called Ichthyosaurus communis, but after studying it more closely, Lomax was convinced it was a rarer one.
After detailed study, he identified it as Protoichthyosaurus prostaxalis. It is the largest example so far known of the species, with a skull almost twice as long as any other specimen.
The fossil only preserved bones from the left side of the braincase. However, using CT scans these elements were digitally mirrored and 3D printed at life size to complete the structure.
Finally, the entire skull was CT scanned using a scanner typically reserved for horses and other large animals.
The research is reported in a paper published in the journal PeerJ.