Scientific name: †Thalassotitan atrox (Longrich et al., 2022) Old named as Prognathodon - Partial dentary with 2 Teeth + 1 germ emerging replacement tooth. Location: Oued Zem, Morocco Geological Formation: Ouled Abdoun Basin (Phosphate beds) Age: Upper Cretaceous, Maastrichtian stage, (~66 Million Years) Size: 12,5cm long Ref: S352 Observations: This enormous Thalassotitan atrox its one of the largest known mosasaur species ( old named as Prognathodon sp). This is a fragment of the dentary (jaw) of this mosasaur species. It preserves 2 teeth + 1 germ emerging replacement tooth. Regarding restorations and repairs: During excavation, the specimen suffered several fractures, including the teeth, which fell apart and had to be reattached to the jaw using the filling method. Even so, it is a magnificent, authentic example of the dentition of this huge mosasaur species. Another very interesting aspect of this specimen is that a germ-emerging replacement tooth is visible within one dentary alveoli . Mosasaurs, like sharks or terrestrial dinosaurs, continuously replace their teeth throughout their lives. When a tooth begins to wear down, a new one starts to grow underneath and replaces it. Here is a magnificent example. Diagnosis: Large mosasaurid, Premaxilla tip short and blunt. Interlocking contacts between premaxilla and maxilla. Maxilla deep, ventral margin convex. Interdigitating joint between maxilla and prefrontal formed by a series of tongue-and-groove joints, with margins of the joint interdigitating. Prefrontal broadly overlaps onto frontal. Prefrontal-postorbitofrontal excluding frontal from orbital margin. Frontal short, broad, strongly constricted anteriorly and strongly concave at contact with parietal anterolateral wings; postorbital processes displaced anteriorly; large posteromedial processes wrapping around parietal foramen. Jugal broad and robust where its contacts the maxilla. Quadrate massive with large, fused supra- and infrastapedial processes below median part of the shaft. Tooth crowns with anastomosed ornamentation of apex and serrated anterior and posterior carinae. Its the most common specie in moroccan phosphates. All our fossils come with Certificate of Authenticity. Every week, the issued Certificates of Authenticity are updated in our website database verification system. If you find that your certificate has not yet been updated, please contact us and we will update it immediately. Display not included. IMPORTANT SHIPPING INFORMATION: All shipments to the USA are sent via UPS Express. We are not responsible for any additional tariff charges that US Customs may add as import fees on the declared commercial value.