PREFERENTIAL ORIENTATION OF DINOSAUR TRACKS IN THE LATE CRETACEOUS FERRON SANDSTONE, CENTRAL UTAH

Many explanations have been utilized over time to attempt to infer behavior of preferentially oriented dinosaur tracks. This study utilized track orientation data collected from one surface (Mary Ann’s Tracksite) in the Late Cretaceous Ferron Sandstone in order to ascertain any preference in directionality of the tracks and trackmakers. These tracks occur as molds on the sandstone surface. Fifty-two of the most well-defined tridactyl dinosaur tracks were chosen for this analysis. Orientation data was collected along the bisecting (long or length) axis of digit III toward the anterior portion of the tracks. Comparison of the mapped track surface to that of individual measurements show that there is some small variation added to the orientation measurements due to the rotation angles of opposite feet in relation to the trackway midline (where present). Overall, data still shows that there are two preferential directions: one direction to the NW - SE (120 - 150°; 300 - 330°) and one direction to the NE - SW (40 - 90°; 220 - 270°). Bedform orientations from the axis of long connected ripple crests on the track surface are approximately at 40° (120°) indicating a possible perpendicular relationship to an adjacent water body. The relationship between the direction of the ripple crests and those of the dominant track directions may indicate a barrier forcing a heading (i.e., walking along the shoreline). The other dominant direction alludes to travel to and from the water body direction (perpendicular to the ripple crests). The indication of bidirectionality in the preferred track directions suggest that interpreting these directional patterns solely as the result of gregarious behaviors is unlikely.