Mathematical determination of coiled shell volumes and surface areas

Mathematical models of shells enable researchers to estimate the maximum possible sizes of organisms that once occupied fossil shells. In this study, a whorl‐by‐whorl method of determining coiled shell volumes and surface areas is introduced. The whorl‐by‐whorl analysis yielded results that were more accurate than those obtained from a model that assumes isometric growth, when both were used to calculate volumes of gastropod shells. The whorl‐by‐whorl method is more laborious, but it is better suited for the analysis of shells exhibiting allometric variation than are methods that use models of isometric growth.