English: 3D rendering of the cranial endocast, cranial nerves, endosseous labyrinth, and as-sociated structures of the holotype fossil of Irritator challengeri (SMNS 58022). (a) right lat-eral view; (b) oblique view, roughly anterolaterally oriented; (c) ventral view; (d) dorsal view. Scale bar equals 30 mm. Abbreviations: cerh, cerebral hemisphere; dp, dural peak; flc, floc-cular recess; III, oculomotor nerve; IV, trochlear nerve; IX–XI, endocast of the metotic fissure, holding the glossopharyngeal (IX), vagus (X), and accessory (XI) nerves; lab, endosseous lab-yrinth; olb, olfactory bulb; olbs, olfactory bulb sulcus; olt, olfactory tract; pit, pituitary; V, trigeminal nerve; VI, abducens nerve; VII, facial nerve; vcm, dorsal middle cerebral vein; XII, hypoglossal nerve.