Meeting Abstract
The transition of life onto land was a pivotal moment in evolutionary history. In order to better understand this important event, we can look to the closest relative of early tetrapods: the lungfish. These fish have been studied primarily to understand the physiological changes which must have taken place to allow for life on land, but their terrestrial locomotion is a significant characteristic which can inform the water-to-land transition as well. Snakes, which rely on axial locomotion, can be good models for describing the terrestrial locomotion of amphibious fish, but the differences in musculature and the axial skeleton mean that the locomotion of amphibious fish must be examined independently. This research assessed the locomotion of the South American Lungfish, Lepidosiren paradoxa, in water and on three terrestrial substrates: sand, loose pebbles, and fixed pebbles, to understand how substrate affects their locomotion. While there was a distinction between aquatic and terrestrial locomotion, the type of substrate did not affect the locomotor performance. However, this may have conferred an advantage to the ancestors of early tetrapods by allowing them to effectively invade new terrestrial territory regardless of the substrate composition and thus may have been essential in the water-to-land transition.
