Article: Technique for scale modelling of cephalopod shells

Previous work by Raup on the mathematical description of coiled shells provides a foundation for the construction of three-dimensional scale models of cephalopod shells. A computer programme, based on the method of Raup, has been developed which contours planispiral surfaces of the cephalopod type. The computer output is then used to construct plastic models of these surfaces. The morphological range covered by this programme includes the entire suite of planispiral cephalopod forms. Provision is made for the simulation of both actual fossil species and hypothetical morphologies. In addition, mathematical simulation of accretionary growth allows the modelling of different stages of ontogenetic series.