Scanner examines ancient footprints

1 min read

A British geoarchaeologist is revealing detailed information about the foot anatomy and gait of ancient human species using optical laser scanners.

Matthew Bennett, a professor of environmental and geographical sciences at Bournemouth University, demonstrated how optical laser scanners can be used to capture the morphology of ancient footprints to within a fraction of a millimetre.

He claims that his geoarchaeology team is the first to use the scanning technology on an excavation site. According to Bennett, the scanners are usually housed in controlled environments because their red lights can be easily bleached from sunlight.

His team designed a rig made of carbon fibre to control the light and dust that can affect the scanners’ performance.

Once a site is excavated to reveal footprints, the generator-powered device is systematically moved across the surface. Along the way, it scans the prints and produces points of the surface.

The prints are then taken back to a laboratory to post process the point clouds. Images of the footprints are then produced and analysed using software developed at Liverpool University.

According to Bennett, this process allows his team to attain geometric and morphometric data about the footprints. ‘It allows us to make quantitative comparisons between different footprints and different human species in our ancestoral line,’ he said.

Bennett added that footprints are more commonly analysed in a subjective manner by creating casts of the prints and theorising on the meaning of their shape and size.

Some groups have used portable LIDAR devices for large-scale surveying to build up 3D models of large objects. However, these devices take points 5mm apart, said Bennett, and they cannot achieve scanning at a scale of 3,000 points within a half metre square. ‘We’re the only people at the moment using it at that scale in a field-based setting,’ he added.

Bennett recently received attention for using his technique in Ileret, northern Kenya, where he scanned footprints left by Homo erectus 1.51 to 1.53 million years ago. Through his research, Bennett discovered that Homo erectus had a modern foot anatomy and walked much like humans today.

‘Homo erectus is the first species to get out of Africa and we know now that one of the reasons it was able to get out of Africa is that it was able to walk properly,’ he said.

Siobhan Wagner