Argentinonectes

Argentinonectes is an extinct genus of elasmosaurid plesiosaur in the group Weddellonectia, known from the Late Cretaceous Calafate Formation of Argentina. The genus contains a single species, Argentinonectes calafatensis, named and described in 2026 based on a partial articulated skeleton that was discovered in 2009. This specimen was found under 50 cm (20 in) of water in Lake Argentino, which complicated its excavation. It includes most of the vertebral column, parts of the pectoral and pelvic girdles, one forelimb, and both hindlimbs, making it the most complete plesiosaur fossil known from Argentina. The articulated rib cage and gastralia indicate the torso would have been very rigid in life. Tooth scratches on some of the bones and tooth fossils found nearby indicate the carcass was scavenged by sharks before it was buried.