Figure 1. Pachyrhachis problematicus (HUJ-PAL 3659) images demonstrating the state of preservation and conservation at the time of restudy by Caldwell and Lee (1997) and Rieppel and Zaher (1999b). 1.1, resin plaque exposing ventral view of specimen. approximately 18 cm long. 1.2, dorsal surface of the skull viewed through resin. scale in millimeters. 1.3, radiograph employed by Rieppel and Zaher (1999b), scale as in 1.2.