Meeting Abstract

67.6  Monday, Jan. 6 09:15  Using experimental and simulated footprints to interpret dinosaur limb motion FALKINGHAM, P L *; GATESY, S M ; Royal Veterinary College; Brown University pfalkingham@rvc.ac.uk

Dinosaur tracks offer a primary source of evidence for understanding not only the behaviours of individual taxa, but also the broader view of locomotor evolution through time. Track morphology emerges from the dynamic, coupled interaction between moving feet and substrate. Deep tracks, in which the foot has penetrated far into the sediment, record the most kinematic data. However, traditional methods of analysis (2D surface outlines) fail to capture the fundamentally volumetric nature of deep track morphology and formation essential to their interpretation. In order to fully extract these data, we must visualize sub-surface foot movements and sediment responses within opaque substrates. To this end, we analysed guineafowl traversing a bed of poppy seeds, using X-ray Reconstruction of Moving Morphology (XROMM) to reconstruct the 3D kinematics of the distal limb both above and below the surface for the first time. Guineafowl limb morphology and motion were incorporated into a discrete element simulation to produce virtual tracks in which the motion of individual particles could be dynamically observed. By combining experimental data with simulations, we were able to reconstruct foot motion paths and the reaction forces in the sediment of a 200 million year old fossil dinosaur track.