Aristonectes quiriquinensis

Aristonectinae is a clade of highly derived elasmosaurid plesiosaurs found in upper Campanian–Maastrichtian (70–65 Ma) sediments, exclusively along the Southern Hemisphere, in a geoecologic realm known as the Weddellian Province (Zinsmeister,
1979).
The holotype of Aristonectes quiriquinensis (SGO.PV.957)
was recovered from limestones exposed on the coast of the locality of Cocholgue, in the Biobío Region of central Chile
https://www.tandfonline.com/doi/abs/10.1080/02724634.2013.780953