The throat musculature of Sphenodon, with comments on the primitive character states of the throat muscles in lizards.

The throat musculature of Sphenodon is described and figured, and compared with that of lizards. In many features of its throat musculature, Sphenodon may well represent a primitive lepidosaurian pattern, comparable to some extent to the chelonian structure of throat musculature. To infer primitive character states within extant lizards, one cannot simply extrapolate from the condition observed in Sphenodon. In fact, it must be assumed that a rapid change of many features of the throat muscles occurred during the early evolution of lizards in order to provide the basis for further differentiation with extant lacertilian infraorders.