Meeting Abstract
The vertebral column is a defining feature of vertebrates and has undergone various changes to support the functional demands faced by different species. One such change is the elongation of the body via addition of vertebrae accompanied by the loss of limbs. Among vertebrate lineages that have evolved such body shapes, squamates (snakes and lizards) are notable because this body shape has evolved at least 25 times, associated with fossoriality or inhabiting complex surface habitats like dense vegetation. And while both snakes and legless lizards have achieved elongation via addition of vertebrae, snakes have many more vertebrae (200–300) when compared to legless lizards (up to 110 vertebrae). These subtle differences in how elongation was achieved may have consequences on the kinematics of these animals. To test this, we compared vertebral and axial kinematics of the European glass lizard (Ophisaurus apodus), the Northern water snake (Nerodia sipedon), and the robustly-limbed fire skink (Riopa fernandi) as they travelled through narrow channels and fields of regularly spaced pegs. Preliminary findings suggest no differences in intervertebral joint angles regardless of the type of habitat treatment. Axial kinematics of the elongate O. apodus and N. sipedon were more similar than they are to those of R. fernandi. Thus, differences in how body elongation was achieved in the legless lizard and snake had no effect on the axial and vertebral kinematics of the species we tested.
