Display in the SA Museum foyer

Icthyosaur skull fossils

Skull bones with model mesh

Stills from the animation

Australia, 120 million years ago

South Australian Museum - Icthyosaur Modelling Project

Dr. Ben Kear, SA Museum, and School of Environmental and Earth Sciences, University of Adelaide

The South Australian Museum enjoys a globally significant collection of palaeontology specimens including unique and well-preserved fossil remains of ichthyosaurs, marine reptiles from the Mesozoic period.

In collaboration with Dr Benjamin Kear, a vertebrate palaeontologist from the SA Museum and the University of Adelaide, and Ben Hill, a student from the University of South Australia, SAPAC provided advanced computing and visualisation support for a project to reconstruct the head of one such ichthyosaur.

With Dr Kear's advice, Ben Hill created a three-part computer model of the skull of an ichthyosaur. The model is as anatomically accurate as possible, including the size and position of the muscles controlling the jaw, the position of the eye and possible location and shape of the "nose".

The base of the model is a scan of a well-preserved ichthyosaur skull; on this were built several major muscles (from scars left on the skull) and then the external surface of the ichthyosaur.

The skull was scanned at the Queen Elizabeth Hospital. The DICOM images were then converted to .stl format (using Osirix) and imported into Rhino for the reconstruction and eventual animation using Quicktime Pro.

The last image at left shows an estimation of the position of and appearance of Australia around 120 millions years ago, somewhat older than the time of the pictured fossil (108Ma BP), but sill in the time of the icthyosaurs. A number of marine fossils (including those discussed here) have been found in areas of Australia that are now well inland; studies of the geological history of Australia show that it once had a major inland sea, as shown in this image. This image is based on palaeotectonic maps kindly provided by Dr. Ron Blakey of Northern Arizona University.

Click MOV to view the animation as a QuickTime movie (4.1Mb MOV, Sorenson 3, 240x180 pixels, 64 seconds, 25 fps, copyright Ben Hill 2007)

Click AVI to view the animation as an AVI (1.8Mb, Indeo 5.1, 240x180 pixels, 64 seconds, 25fps, copyright Ben Hill 2007)