Figure 8. Skull of Pachyrhachis problematicus (HUJ-PAL 3659) in dorsal view and serial sections, illustrating mental foramen path and crushed regions. 8.1, dorsal view, computer generated reconstruction. Arrow 3 indicates depression identified by Caldwell and Lee (1997) as a second mental foramen. Arrow 1 indicates similar crushed region superficially resembling mental foramen; arrow 2 points to true mental foramen. 8.2 and 8.3, serial sections illustrating the relationship of the anterior crushed region, manifested in the superficial anterior depression in 8.1, arrow 1; 8.4-8.7, sequential serial sections demonstrating the relationship of external morphology to internal crushed regions. In serial section 8.7, the foramen indicated by arrow 2 can be traced through the sections without interruption; however, the superficial depressions mimicking foramina directly overlay crushed regions. Arrow 3 overlies the area weakened by the void of the Meckel’s groove below and the anterior surangular suture above, and arrow 1 overlies the anterior crushed region formed by coronal rotation of the anterior dentaries. Scale bar equals one centimeter.