A long-snouted and long-necked polycotylid plesiosaur from the Late Cretaceous of North America.

ABSTRACT: Plesiosaurs are a group of Mesozoic marine diapsids. Most derived plesiosaurs fall into one of two typical body forms: those with proportionately small heads, short snouts, and elongated necks, and those with large heads, elongated snouts, and short necks. Serpentisuchops pfisterae is a polycotylid plesiosaur from the Upper Cretaceous Pierre Shale that presents the trait combination of both an elongate snout and elongate neck (consisting of 32 vertebrae). Phylogenetic analysis places Serpentisuchops within the Polycotylinae, indicating that its long snout is an ancestral trait, while its long neck is secondarily derived and convergent with that of ancestral plesiosaurs, contemporaneous elasmosaurids, and some more basal members of the Polycotylidae. The conical, recurved, and

SUBMITTER: Persons WS 

PROVIDER: S-EPMC9617461 | biostudies-literature | 2022 Oct

REPOSITORIES: biostudies-literature