Figures & data
Figure 1. The origin of bone. Precipitation of hydroxyapatite around the basal membrane of the skin gave rise to enamel- and dentine-like tissues that formed odontodes, which became the progenitors of teeth and scales. Spread of mineralization deeper in the dermis formed shields consisting of acellular—and later cellular—bone. (Adapted from Donoghue et al. Citation2006).
Figure 2. The role of predation.
Figure 3. Major gene networks that govern skeletal evolution. Arrows indicate positive interactions and horizontal lines indicate negative interactions. The scheme depicts signaling pathways as they are currently understood, but most of the processes are under intensive investigation. The information has been taken from multiple sources that are cited throughout the text.
