Computer Aided Retrodeformation Techniques

A technique whereby a deformed fossil is restored to its original shape is termed retrodeformation. This paper develops four such techniques designed to encompass a broad range of fossil types. The retrodeformation techniques are tested using fossil forms developed by a three dimensional graphics application programming interface, PHIGS and PHIGS PLUS. 1 Introduction Deformed fossils can provide valuable information on the state of strain in a rock. They are easily measured and analysed using the strain techniques described by Ramsey (1967) [Ram67] and Ramsey and Huber (1983) [RH83]. However this deformation is troublesome to the palaeontologists (someone studying all aspects of ancient organisms, including their anatomy, ecology and evolution (Stiegeler 1978) [Sti78]). Features used for specific discrimination, such as measurements and line to width ratios, become altered. An assessment of strain is essential for the determination of deformed fossils, but because palaeontologists rel..