Meeting Abstract
An elastic-recoil mechanism of tongue projection in plethodontid salamanders provides benefits to terrestrial feeding including high-powered dynamic movements and thermal insensitivity, advantages not found in non-elastic, muscle-powered movements such as tongue retraction. This high-powered feeding mechanism evolved independently within the Plethodontidae by modification of an existing non-elastic mechanism. We examined feeding performance and morphology of the plethodontid salamander Hemidactylium scutatum and compared its functional morphology to its close relatives Batrachoseps and Bolitoglossini. Morphological examination, high-speed imaging (10 kHz), and inverse dynamics analysis reveals that Hemidactylium utilizes elastically powered tongue projection (~6000 W/kg muscle mass) and has muscle-powered, non-elastic tongue retraction, yet retains some ancestral morphological characters compared to its close relatives. The intermediate morphology of Hemidactylium provides insight into how elastic mechanisms have evolved in plethodontids and which components are necessary to increase tongue-projection performance.
