EXTENSIONS OF RECONSTRUCTION TECHNIQUES

Whole fossil reconstructions

Reconstructions from a single grinding run typically comprise just part of a fossil, as grinding normally commences from the plane along which the nodule was originally fractured. Reconstructions of entire fossils may be obtained by gluing part and counterpart together before sawing to size so that the entire fossil can then be ground through as one unit. However, this approach can produce artifacts from imperfect alignment of the glued surfaces or from the glue itself. Alternatively and more satisfactorily, part and counterpart can be reconstructed separately and reassembled digitally before rendering. Figure 13 is an example of a whole fossil reconstructed in this way.

Dissection of models

Reconstructions of portions of a fossil, or of a subset of the structures present, are often of great utility. A strength of the volume-based approach described here is the ease with which such ‘dissected’ reconstructions can be prepared. Copies of the appropriate slice images are simply manipulated using image editing software to remove structures or portions of the fossil that are not required (see Appendix 1, section 3), and are then rendered in the normal way. Slice videos and pre-dissection three-dimensional reconstructions provide the ideal tools to guide such dissection work, and ensure that unwanted structures are removed accurately.