The development of the trigeminal jaw adductor musculature and associated skull elements in the lizard Podarcis sicula



The ontogenetic development of the jaw adductor musculature in Podarcis sicula (Raftnesque) is described in detail and related to patterns of ossification in associated skull elements. It was found that the coronoid bone ossifies in continuity with the developing bodenaponeurosis, whereas the elements of the upper temporal arcade ossify prior to (and seemingly independently of) the realization of an attachment of the developing jaw adductors.

Various aspects of the development of the jaw adductors are discussed in the light of theoretical claims concerning conflicting models of ontogeny, as is the role of ontogenetic studies in the determination of character polarity. It is concluded that the present study supports the model of epigenetic development, and that ontogeny alone is insufficient for the assessment of character polarity. Instead, ontogeny must be interpreted in the context of phylogenetic hypotheses.