Meeting Abstract
26.3 Saturday, Jan. 4 14:00 Sprawling locomotion: how similar are kinematics and dynamics in a sample of five phylogenetically, ecologically and morphologically diverse tetrapods? NYAKATURA, J.A.*; ALLEN, V.R.; Friedrich-Schiller-Universität, Jena, Germany; Friedrich-Schiller-Univeristät, Jena, Germany and Royal Veterinary College, London, UK john.nyakatura@uni-jena.de
Sprawling locomotion is utilized by a wide range of extinct and extant non-erect species. Moreover, this locomotor mode likely is basal to crown group tetrapods and thus fundamental for the understanding of terrestriality in tetrapod evolution. Sprawling locomotion is characterized by complex three dimensional movements of the limbs, including important long-axis-rotation of the humeri and femora. This made quantitative comparisons notoriously difficult in the past. To identify common principles in the locomotor mechanics of tetrapods, we currently study the locomotor mechanics of the fore- and hindlimbs in four phylogenetically, ecologically and morphologically different species: metamorphosed axolotls (Ambystoma mexicanum), ribbed newts (Pleurodeles waltl), blue-tongued skinks (Tiliqua scincoides), green iguanas (Iguana iguana), and spectacled caimans (Caiman crocodylus). We use x-ray reconstruction of moving morphology (XROMM) and simultaneous ground reaction force measurements of individual limbs to study the kinematics and dynamics of these species’ sprawling locomotion. Differences in relative limb segment proportions of our sample inevitably lead to kinematic differences. We are interested in how the kinematic differences are reflected in the contributions of individual limb joints to progression. This knowledge could be used to constrain paleontological inference of locomotor characteristics in early crown group tetrapods.
