Thalassotitan, meaning "titan of the seas", is an extinct genus of large mosasaurs (a group of extinct marine lizards) that lived during the late Maastrichtian of the Cretaceous period in what is now Morocco, approximately 66 million years ago. The only known species is T. atrox, described in 2022 from fossils discovered in the Ouled Abdoun Basin, where many other mosasaurs have been found. It was assigned to the tribe Prognathodontini along with other mosasaurs such as Prognathodon and Gnathomortis. Prognathodontines are differentiated from other mosasaurs by their massive jaws and robust teeth.
This genus clearly demonstrates that mosasaurs evolved to occupy the dominant predator niche in Late Cretaceous oceans, which is now occupied by sharks and killer whales. Severe wear on its teeth and fossils found in the vicinity of the holotype, eroded by partial digestion, suggest that this mosasaur fed on smaller species of mosasaurs, plesiosaurs, large predatory fish and sea turtles.
The genus name Thalassotitan is a portmanteau of the Ancient Greek θάλασσα (thalassa, "sea") and τιτάν (titan, "giant"), referring to the large size of the mosasaur. The specific epithet atrox is a Latin word meaning "cruel" or "merciless", which refers to the species' trophic position as a top predator and the frequency of intraspecific bite marks in fossils.
Thalassotitan was one of the largest mosasaurs. Its skull measured up to 1.3 meters in length, corresponding to a total length of 9-10 meters.
The skull of Thalassotitan is blunt and robust. The premaxilla, the bone that bears the tip of the skull, is very short in lateral view but wide and convex when viewed dorsally. The body of the premaxilla contains numerous pits called neurovascular foramina, which are believed to house tactile nerves that are highly sensitive to touch. The jugal bone, located just below the eye, is broad and robust. The frontal is short and wide, with large neurovascular foramina in the center. The supratemporal fenestrae, large openings between the eyes and the back of the skull, occupy almost a quarter of the total length of the skull and are somewhat triangular.
Thalassotitan's teeth are approximately conical, slightly curved, large and robust. They are most similar to the teeth of P. saturator except for being slightly shorter and more robust. Dental crowns are generally smooth but can sometimes have weak ridges. The cutting edges are well developed and finely serrated.
The description of the postcranial skeleton is not completely known, only fossils have been found that represent a little more than half of the anterior body. The general shape of the vertebrae is typical of mosasaurines. They are procellous, meaning the front side is deeply concave and the back side is convex.
Approximate measurements of Thalassotitan:
This genus clearly demonstrates that mosasaurs evolved to occupy the dominant predator niche in Late Cretaceous oceans, which is now occupied by sharks and killer whales. Severe wear on its teeth and fossils found in the vicinity of the holotype, eroded by partial digestion, suggest that this mosasaur fed on smaller species of mosasaurs, plesiosaurs, large predatory fish and sea turtles.
The genus name Thalassotitan is a portmanteau of the Ancient Greek θάλασσα (thalassa, "sea") and τιτάν (titan, "giant"), referring to the large size of the mosasaur. The specific epithet atrox is a Latin word meaning "cruel" or "merciless", which refers to the species' trophic position as a top predator and the frequency of intraspecific bite marks in fossils.
Thalassotitan was one of the largest mosasaurs. Its skull measured up to 1.3 meters in length, corresponding to a total length of 9-10 meters.
The skull of Thalassotitan is blunt and robust. The premaxilla, the bone that bears the tip of the skull, is very short in lateral view but wide and convex when viewed dorsally. The body of the premaxilla contains numerous pits called neurovascular foramina, which are believed to house tactile nerves that are highly sensitive to touch. The jugal bone, located just below the eye, is broad and robust. The frontal is short and wide, with large neurovascular foramina in the center. The supratemporal fenestrae, large openings between the eyes and the back of the skull, occupy almost a quarter of the total length of the skull and are somewhat triangular.
Thalassotitan's teeth are approximately conical, slightly curved, large and robust. They are most similar to the teeth of P. saturator except for being slightly shorter and more robust. Dental crowns are generally smooth but can sometimes have weak ridges. The cutting edges are well developed and finely serrated.
The description of the postcranial skeleton is not completely known, only fossils have been found that represent a little more than half of the anterior body. The general shape of the vertebrae is typical of mosasaurines. They are procellous, meaning the front side is deeply concave and the back side is convex.
Approximate measurements of Thalassotitan:
- Scale 1:60 - Complete
- Length 73mm
- Height 58mm
- Width 43mm
- Snout-tail length 146 mm
- Scale 1:35 - Complete
- Length 126mm
- Height 98mm
- Width 73mm
- Snout-tail length 250 mm
