DEUFEL, A.; NETT, J.L.*; Minot State University; Minot State University: Strike Kinematics in Death Adders: Convergence with Vipers?

Death adders (Acanthophis) are terrestrial elapids who superficially resemble vipers. They are ambush hunters with large, triangular heads, slender necks, and stout bodies. Elapids and vipers differ significantly in cranial musculoskeletal morphology. Differences relating to prey capture kinematics exist mainly in maxillary morphology and relationships, palato-pterygoid bar connections, and the dorsal constrictor muscles. Vipers, even though they are basal colubroids, are considered to have the most optimized prey capture apparatus, whereas elapids are less modified compared to non-venomous snakes and achieve their greatest diversity where vipers are absent. We examined prey capture kinematics and their morphological correlates in Acanthophis antarcticus and compared them to published reports of terrestrial vipers. Prey capture in Acanthophis only superficially resembles vipers. Prey capture differs from vipers in that Acanthophis initiates strikes when prey is very close, almost never releases prey after the strike, and has lesser maxillary mobility. Like in vipers and other hydrophiine elapids, but not elapines, the palatine of Acanthophis has no connections to the maxilla, choanal passage, or snout, potentially allowing greater excursions of the jaw apparatus. The origin of the protractor pterygoideus is relatively anterior compared to other elapids but does not approach the extreme elongation seen in vipers. Anterior origin of the muscle facilitates large palatomaxillary protraction, and may explain how Acanthophis begins to approach viper-like prey capture kinematics. Acanthophis slightly modified the typical elapid morphology which allowed it to approach but not achieve viper-like kinematics. Elapids remain less optimized for prey capture than vipers.