Usually, fossil reconstruction is like a three-dimensional puzzle.
The problem is that some parts are missing, and some parts are sometimes distorted.
We take these pieces and put them into a medical CT scanner so we can get three-dimensional X-rays,
and what you end up with is hundreds of slices like this.
And from these slices you can reconstruct the original form.
We have a distortion here on the skull:
between the parietal bone and the temporal bone there’s a gap.
So we can use the computer to move the part around,
so we can interact with the fossil without, you know, damaging the original.
We try to correct as much as we can manually by, you know,
rotating parts that don’t fit together and making them fit again,
or using symmetry to mirror missing parts from one side to the other.
When parts are missing on both sides, you have to make predictions and basically you have to guess.
And what we want to do is, what you usually do in traditional anthropology,
is you take plaster or plasticine and model the missing parts as how you think they should have been.
We try to do predictions using the computer.
We measure hundreds of points on complete skulls of the same species--fossil species, for example.
And we use the computer to estimate the parts that are missing.
So here we have a three-dimensional image of this skull that's a pre-Neanderthal--
a Homo heidelbergensis from France, in Arago.
And you can see that it was heavily distorted during fossilization.
So, all this is shifted.
And what we try to do is, we correct for this distortion by making it perfectly symmetric again.
And that's one of the big advantages of working with these digital data,
is that you can use the computer to correct for such distortions.