Figure 10.1. A comparison of four Tyrannosaurus rex skulls. A, CM 9380 (formerly AMNH 973); B, AMNH 5027; C, LACM 23844; D, TMP 81.6.1; E, SDSM 12047. The reconstruction of CM 9380 differs from that given by Osborn (1906) in the orbital and postorbital regions. Osborn had erroneously used the right ectoptygoid as a right postorbital in the reconstructed skull at the Carnegie Museum. As may be seen in the figure, the squamosal no longer extends into the orbit. TMP 81.6.1 is more complete than shown, but preparation was not complete at the time this figure was made. SDSM 12047 is crushed dorsolaterally, which has greatly affected the snout, no attempt has been made to compensate for this. (Scale bar = lOcm.)