Feeding Mechanisms in Pygopodid Lizards: How Can Lialis Swallow Such Large Prey?

Most species of the Australian legless lizards (Pygopodidae) feed primarily on ar- thropods, but one genus (Lialis) feeds on other lizards, chiefly skinks. Feeding behavior and struc- ture of the skull and jaw muscles were studied in Lialis burtonis, Pygopus lepidopodus and Delma inornata. Pygopus and Delma resemble other gekkotan lizards in these respects, but Lialis is con- vergent on saurophagous snakes. In particular, Lialis possesses (i) pointed, recurved, hinged teeth, (ii) highly mobile mesokinetic and hypokinetic joints, and (iii) an extraordinarily elongate skull. All of these modifications can be interpreted as adaptations to increase the ability of Lialis to seize, handle and ingest large scincid prey. Further work is required to distinguish among alternative hypotheses on the roles of these cranial modifications.