A Giant Pliosaurid Skull from the Late Jurassic of England

摘要: Pliosaurids were a long-lived and cosmopolitan group of marine predators that spanned 110 million years occupied the upper tiers ecosystems from Middle Jurassic until early Late Cretaceous. A well-preserved giant pliosaurid skull Kimmeridge Clay Formation Dorset, United Kingdom, represents new species, Pliosaurus kevani. This specimen is described in detail, taxonomy systematics pliosaurids revised. We name two additional carpenteri westburyensis, based on previously relatively complete, remains. Most or all represent globally distributed monophyletic (the genus Pliosaurus, excluding ‘Pliosaurus’ andrewsi). Despite its high species diversity, geographically widespread, temporally extensive occurrence, shows less morphological ecological variation than seen earlier, multi-genus assemblages such as Oxford Formation. It also pliosaurid-like Cretaceous clade Polycotylidae. Species had robust skulls, large body sizes (with lengths 1.7–2.1 metres), trihedral subtrihedral teeth suggesting macropredaceous habits. Our data support trend decreasing length mandibular symphysis through time, suggested. may be correlated with increasing adaptation to feeding prey. Maximum size increased their first appearance Early (skull up 2360 mm). However, some reduction occurred before final extinction 1750