For the Manis rib fragments, this meant isolating each piece of the embedded bone material from the surrounding trabecular and cortical bone of the rib, creating individual digital models of each fragment.

Once the fragments were individually modeled, the researchers could begin the reconstruction process: examining each fragment’s surface geometry and attempting to identify the matching surfaces — the fractured faces — that would have been in contact before the impact that broke the object apart.

Fractured surfaces have characteristic geometries: the way a brittle material breaks leaves specific surface textures and angles that are mirror images of each other on the two pieces.

Finding matching fractured surfaces between different fragments allows the pieces to be fitted back together in the correct relative position.