Permanent record: The use of dental and bone microstructure to assess life history evolution and ecology

Abstract

In order to study the impact of ecology on life history evolution, paleobiologists have begun to take a cue from dendrochronology, and have increasingly been making use of microstructural growth records available within mineralized tissues: dental enamel, dentin, and bone. These tissues contain regular growth increments whose periodicities range from 24-hour (circadian), to 2-week, to seasonal and annual cycles, and which have allowed us to generate absolute chronologies of growth in teeth and bone. The study of these increments is known as odontochronology with respect to teeth, and skeletochronology with respect to bone. These two related fields allow us to directly quantify how species’ growth patterns are correlated with a number of ecological factors over geological time. Moreover, because growth increments record individual stress events that occurred within individual animals’ lifetimes, they allow us to observe important ecological pressures that occurred on shorter timescales as well.