ABSTRACT
This chapter focuses on some of the problematic anatomies that have plagued the science of snake lizard morphological and anatomical interpretation, particularly as concerns modern snake lizards. In non-snake lizards, there are nine elements that frame the orbit: the frontal, prefrontal, lacrimal, maxilla, jugal, ectopterygoid, postorbital, postfrontal, and, in a few species, the supraorbital or palpebrals. Admittedly, the same top–down essentialism noted for the jugal-postorbital debate is present in the debate on the “crista circumfenestralis”, but in reality, the real difficulty is the complexity of the anatomy. The membranous labyrinth is also fluid filled—endolymph—and that fluid moves through and past the various sensory structures, all of which support the sensory functions of hearing and equilibrium. The more lateral component of the middle ear complex in snake lizards varies somewhat between many modern snake lizards and in particular Mesozoic-aged fossil snake lizards.
