The oldest elasmosaurs (Sauropterygia, Plesiosauria) from Antarctica, Santa Marta Formation (upper Coniacian? Santonianupper Campanian) and Snow Hill Island Formation (upper Campanianlower Maastrichtian), James Ross Island

Abstract

Elasmosaurs are recorded for the first time in the Beta Member (middle levels of Lachman Crags Member) of the Santa Marta Formation (lower Campanian) and Herbert Sound Member of the Snow Hill Island Formation (upper Campanian). These are the first elasmosaurids from James Ross Island, Antarctic Peninsula. This record enlarges the taxonomic diversity of plesiosaurs of the Santa Marta Formation and Herbert Sound Member of the Snow Hill Island Formation and extends the lower limit of the record of Elasmosauridae in Antarctica to the lower Campanian, thus being the oldest record of an Antarctic elasmosaur.