The discovery in a quarry near Elgin of a hole in a block of red sandstone has led to what local palaeontologists have heralded as one of the most exciting fossil discoveries of the century.

With the help of modern medical scanning techniques, the results have been more precise and productive than with any methods previously used.

And much like the plot of Jurassic Park 3, experts have turned to Rapid Prototyping to advance their research and bring their discoveries to life!

The block was discovered in North East Scotland in 1997 when quarrymen (Moray Stone Cutters) noticed a hole in the rock while digging stone. Realising that it may be of importance, they set the rock aside and contacted a local Open University student, Carol Hopkins. Upon examining the sandstone block, Carol confirmed that the hole represented the mould of fossil bone.

Mouldic fossils form when the animal bones are completely dissolved away inside the rock to leave a void. Traditionally the moulds of fossil animals were cast in rubber by filling the holes and splitting the rock, thus damaging the mould, and not always producing a satisfactory impression.

To avoid damage to the mould, Dr. Neil Clark from Glasgow University's Hunterian Museum decided to employ non-invasive techniques using modern medical scanners as well as the very latest model making methods. Initial results, as featured on Tomorrows World, were encouraging.

Dr. Clark explained, ''CT-scanning was performed in the first instance. From the first scan, it was obvious that we were dealing with the entire skull of a mammal-like reptile (dicynodont). Rendering the CT-scans produced a 3-D image of the skull which allowed us to compare it with similar fossils from around the world.'

With the help of Dr Calum Adams of the Royal Alexandra Hospital, Paisley and Tristan Lawton of the Royal Infirmary, Edinburgh, Dr. Clark decided to use a more accurate medical technique to see inside a mouldic fossil for the first time ever.

Magnetic Resonance Imaging, normally used by radiologists to see soft tissue and detect tumours in humans was used in this same way to accurately detect the space in the mouldic fossil.

MRI scanning could provide a better resolution than CT-scanning because of the finer scan thickness. To be detected, the cavity had to be filled with water prior to scanning, as MRI requires a fluid to react with the magnetic field.

The entire skull was then successfully scanned using MRI. The result was a fully accurate 3D image of a 250 million-year-old dicynodont ('two toothed dog')

Laser Prototypes Europe Ltd., Belfast was then approached by Neil who enquired about the possibility of creating a solid model of the skull using Stereolithography.

LPE has several years of experience in working with MRI scanned data from local hospitals but had only ever experienced working with human skulls.

''We have worked extensively with local hospitals on creating SLA patterns to produce titanium plates for insertion or for visual aids for surgeons to help establish corrective surgery methods.

But this was the first time we've been asked to produce a 250 million year old fossil skull,' commented Campbell Evans, LPE's Technical Sales Manager.

Within a couple of days, Dr. Clark received a fully detailed SLA model replicating the exact features of a 250 million year old skull which had hitherto only existed as a cavity in a sandstone rock.

'The amount of detail here is absolutely phenomenal!' Dr. Clark enthused.

''The use of medical scanners and Stereolithography has saved a very important fossil from being damaged by traditional methods of palaeontological investigations. The resolution obtained is enough to identify the species of dicynodont represented by the mouldic skull.

In some parts of the skull, fine structures that would have been lost using rubber casting techniques, were observed and reproduced faithfully in an exact prototype replica of the data.'

So, perhaps Spielberg wasn't too far off the mark in his latest Jurassic Park instalmentﾅﾅﾅ.

Images of the 3D skull can be viewed at Dicynodont Images

Media Relations Office (media@gla.ac.uk)

Dr. Neil Clark can be contacted for further comment via the Press Office on 0141 330 3535

First published: 17 September 2002