Libonectes is an extinct genus of sauropterygian reptile belonging to the plesiosaur order. It is known from specimens found in the Britton Formation of Texas (USA) and the Akrabou Formation of Morocco, which have been dated to the lower Turonian stage of the late Cretaceous period.
Nomenclature[]
The prefix "libo" comes from Greek, and means "southern," translated to English. "Nectes," the suffix, is also from Greek, and translates to "swimmer." In its entirety, Libonectes can be interpreted as "southern swimmer." Libonectes was an elasmosaurid plesiosaur, with many specimens unearthed in southern parts of North America- as a result, it was labeled with such a name as described in the preceding sentence. C.G. Morgan is credited with the discovery of the first Libonectes fossils, and it was for this reason that morgani was chosen as its binomial name.
Description[]
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, which also contains the 5.06 metres (16.6 ft) neck and gastroliths, is the best preserved elasmosaurid skull known. 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 to its own genus by Carpenter in 1997. A second species, L. atlasense, was named in 2005 from deposits in Morocco, but a 2017 redescription of the material recognized it as a junior synonym of L. morgani.