Thalassoceratids

Thalassoceratids are an extinct group of marine reptiles belonging to the order Plesiosauria. These long-necked predators inhabited the oceans during the Mesozoic Era, primarily during the Cretaceous period. Their name, meaning "sea-horned face," refers to a distinctive feature of their skulls, although specific horn-like structures are not always prominent or universally present across all known thalassoceratid species.

Fossil evidence suggests that thalassoceratids were a diverse group, with variations in size and body shape. They were characterized by their elongated necks, which they likely used to search for prey in the water column. Their diet consisted of fish and other marine organisms, which they would have captured using their sharp teeth. The exact evolutionary relationships of thalassoceratids within the plesiosaurian tree are still a subject of scientific research, with ongoing analysis of skeletal remains helping to refine our understanding of their place in the ancient marine ecosystem. Their extinction, like that of many other marine reptiles, is thought to have occurred at the end of the Cretaceous period, possibly due to the K-Pg extinction event.