When workers in a quarry near Elgin stumbled upon the fossil remains of a 250 million year old Dicynodont little did they realise they would one day be able to come face to face with the worlds oldest dog. Using modern medical imaging technology combined with 3D printing Dr. Neil Clark from the Hunterian Museum in Glasgow was able to generate a physical model of the Dicynodont skull without compromising the original moldic fossil.
In order to identify the fossil medical scanning technology was used including MRI and CT scanning. Through the measurement of variations in the internal density of the sandstone block the team were able to create a 3D representation of the fossil. This representation revealed the entire skull of the prehistoric Dicynodont.
With 3D digital renderings of the skull, Dr. Clark then approached Rapid Prototyping bureau Laser Prototypes enquiring about the potential of creating a solid model of the skull using the Stereolithography process.
The first step for the Rapid Prototyping bureau was the conversion of MRI files to a suitable file format (STL). In order to ensure the integrity of the file Laser Prototypes worked closely with the local MRI department to carefully adjust the MRI files. Once created the STL file was then transferred through Rapid Prototyping software, which sliced the image into thin 0.1mm layers and added the necessary support structures. With Watershed selected as the material of choice the sliced file was then sent to the stereolithography machine for printing.
Each layer was then individually drawn by laser onto a surface of light sensitive liquid resin. Upon contact with the laser the resin cured and with the layer drawn the machine platform drops a layer. The laser traces the next layer and the process repeats until a fully “grown model” is produced layer by layer within the vat.
With the 3D model built the machine platform is then raised to lift the model. Once drained the SLA skull was then washed and all supporting structures were removed by hand.
By using medical imaging and rapid prototyping technology it was possible for a 3d model of the skull to be created without compromising the original moldic fossil. Dr. Clark commented “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 moldic 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”.
The 3D printed Dicynodont skull can be seen on display at the Elgin Museum, Scotland.