ABSTRACT
This chapter presents urodeles as the main example to illustrate the development of cephalic muscles in tetrapods. It describes the paper of Ziermann and Diogo (2013) on the development of the axolotl (Urodela: Ambystoma mexicanum), because the authors overall analyses and comparisons indicate that urodeles are the best model to understand the early evolution and thus basal configuration of tetrapod cephalic muscles. In addition to being considered the most useful model organism to discuss the early evolutionary history of tetrapods, the axolotl is also a crucial model for regenerative and evolutionary developmental biology (such as Diogo and Tanaka 2012; Diogo et al. 2014b, c). Among amphibians, several types of metamorphosis are known that involve greater or lesser change between the larval and adult stages.
