METZGER, K.A. *; HERREL, A.; Stony Brook University; University of Antwerp: 3-D analysis of inertial transport in tegus: modulation of jaw and craniocervical kinematics

Inertial transport is a presumably stereotypic form of prey transport that is utilized to move food items from the jaw tips into and through the oral cavity. It has been contrasted with lingual transport as a means for moving food caudally into the pharynx. Once the food item is grasped in the jaws, the head and neck are rapidly rotated or translated backwards and the jaws are opened, releasing the prey. Finally, the head reverses direction and the jaws are closed around the prey. Despite the fact that this is a primary prey transport strategy of several major lepidosaur groups, the nature (i.e., dorsoventral vs. mediolateral orientation) and magnitude (velocity, acceleration) of these movements have never been described in detail. In this study, we use a 3-D VICON system to track and analyze jaw and craniocervical movements during inertial transport in Tupinambis merianae, the black and white tegu. Tupinambis is a large omnivorous lizard, which has been previously demonstrated to use both inertial and lingual transport to varying degrees during feeding. Ten different food items, which varied in type, size and material properties were used in order to examine whether inertial transport kinematics have a high degree of stereotypy or whether they are modulated in response to food properties. In tegus, there are distinct differences between inertial and lingual transport in the kinematics of the jaws and craniocervical apparatus. Additionally, prey properties have a significant effect on the use and nature of inertial transport in this species, with prey items of higher mass and size eliciting an increased use of inertial transports.