A large platypterygiine ichthyosaur from the Late Cretaceous of Poland and its macropredatory adaptations

Abstract

The discovery of a well-preserved rostral cross-section of a platypterygiine ichthyosaur in Cenomanian deposits at Annopol, Poland, provides new insights into the anatomy, functional morphology, and ecological role of this group during the Late Cretaceous. The specimen, identified as Platypterygiinae indet., preserves articulated teeth, a visible interpremaxillary cavity, and neurovascular canal openings, enabling detailed anatomical and comparative analyses. The robust dentition, featuring blunt crowns and deep implantation, suggests adaptations for a hypercarnivorous diet focused on hard and bony prey, such as marine turtles, smaller ichthyosaurs and large actinopterygian fish. Comparative analysis reveals close affinities with other Platypterygiinae, such as Platypterygius australis (Kear, 2005) and Pervushovisaurus spp., while highlighting distinctions from more generalist ophthalmosaurids like Ophthalmosaurus spp. The ecological role of the Annopol ichthyosaur as an apex predator mirrors that of modern marine predators, such as orcas and great white sharks, emphasizing its dominance in Cenomanian marine ecosystems. Its presence reflects the productivity and complexity of these environments, while its extinction at the Cenomanian–Turonian boundary underscores the combined impact of environmental disruptions, including ocean anoxia. This study enhances our understanding of the adaptive strategies, sensory biology, and ecological significance of Late Cretaceous ichthyosaurs, providing a key reference for exploring the evolutionary and ecological dynamics of marine reptiles during a critical period in Earth’s history.