Fig. 3.—Outline of skull of Prozeuglodon atrox with cranial region of Lophocephalus shaded to indicate the relative size of the completed skull. × ½. fr.: frontal bone; ju.: jugal; la.: lambdoidal crest; max.: maxilla; na.: nasal; nos.: nostril; pa.: parietal; pmx.: premaxilla; sag.: Sagittal crest; sq.: squamosal; zy.: zygoma.