Lengthwise atop their skulls ran a thin and shallow sagittal crest that was usually tallest near or above the eyes, either becoming shorter or disappearing entirely towards the front of the head. Spinosaurus's head crest was comb-shaped and bore distinct vertical grooves, while those of Baryonyx and Suchomimus looked like small triangular bumps. Irritators median crest stopped above and behind the eyes in a bulbous, flattened shape. However, given that no fully preserved skulls are known for the genus, the complete shape of Irritator's crest is unknown. Cristatusaurus and Suchomimus (a possible synonym of the former) both had narrow premaxillary crests. Angaturama (a possible synonym of Irritator) had an unusually tall crest on its premaxillae that nearly overhung the tip of the snout with a small forward protrusion.
