there are traces of a tenth tooth in the rock matrix. The teeth were deeply inserted into the jaw and widely spaced towards the front of the maxilla. The first and second preserved maxillary teeth were the largest, at and in crown length. The seven remaining teeth became progressively smaller towards the rear, one of the last ones measuring in estimated crown length. CT scans performed on the specimen revealed replacement teeth on both sides of the upper jaw. Their roots ran deep into the maxillae and converged close to the midline, nearly reaching the top of the skull. Based on comparisons with Irritators relatives, the maxillae were probably lined with a total of 11 teeth each, similar to the number of 12 teeth in MSNM V4047, an upper jaw fossil referred to Spinosaurus. The hindmost tooth of the Irritator specimen's left maxilla was not yet fully erupted, and only the tip of it was visible. Anatomy of the Angaturama limai holotype The holotype of Angaturama limai consists only of the front part of the upper jaw, comprising the tips of the paired premaxillae and the frontmost ends of the maxillae. The specimen measures in height and in length, with the width of the palatal region being . The suture between the maxilla and premaxilla was jagged at the front and straightened out towards the rear. The lower margin of the premaxillae was concave, with the concavity reaching its apex at the sixth premaxillary tooth. The front of the snout was expanded, forming the spoon-shaped terminal rosette characteristic of spinosaurids. This concave underside of the premaxillae would have complemented a convex and enlarged mandible tip. The premaxillae connected with each other on the bottom to form Angaturamas secondary palate, which was also partially contributed to by two processes extending from the maxillae. The snout was strongly compressed laterally, and the premaxillae gently tapered towards the top to form a tall sagittal crest in thickness. This crest was larger and extended farther forwards on the snout than in other known spinosaurids. The frontmost upper border of the premaxilla had a small bulge that overhung the base of the crest. This bulge was apparently damaged on its upper surface, indicating that the top of the crest may have extended even farther over and forwards from that point. The front of Angaturamas snout hence had a vertically straight or concave margin, atypical from