What is "libonectes"

Libonectes (meaning "southwest swimmer") is an extinct genus of sauropterygian reptile belonging to the plesiosaur order. It is known from a single fossil specimen found in the Britton Formation of Texas, USA, dated to the lower Turonian stage of the late Cretaceous period.

The animal was very similar to the related Thalassomedon, though the structure of the neck vertebrae were different, with taller neural spines and longer supporting processes of the bone, and its nostrils were slightly closer to the tip of the skull. The skull of the type specimen is the best preserved elasmosaurid skull known. The specimen consists of the skull and neck, as well as gastroliths found along with the fossil. A shoulder girdle and flipper were also found but were apparently discarded at some point in the past.

The specimen was originally named Elasmosaurus morgani by Welles in 1949, but it was reclassified in its own genus by Carpenter in 1997.