The science of interpreting periodicity in growth, usually in growth bands on bivalve mollusks. Some species grow one band per lunar day! By measuring these growth increments, scientists can discover the environmental conditions of the water in which the shells were grown. The species Arctica Islandica can live up to 230 years, and thus is prized in obtaining longterm data.

Sclerochronology is used in both the reconstruction of paleontological history, and in attempts to predict future weather patterns, among other things.

This field is similar to the study of tree rings (dendrochronology).