Libonectes Skull

''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 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.Carpenter, K. (1999). "Revision of North American elasmosaurs from the Cretaceous of the western interior." ''Paludicola'', 2(2): 148-173.

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''.

Feeding Habits

The possible carnivorous nature of ''Libonectes'' is suggested by its dental layout, however, the presence of gastroliths inside some known fossils feasibly indicates an omnivorous lifestyle (though paleontological investigation notes that plesiosaurs may have used gastroliths in buoyancy control). The presence of these gastroliths could also point to the possibility that ''Libonectes'' swallowed prey items whole. ''Libonectes'' most likely hunted in deep waters, perhaps eating small fish and ammonites, as it is thought that its bulk prevented the creature from frequenting shallow waters. This reptile is also suspected to have used its large size to trap prey, as a result of its slow swimming speed.

See also

*List of plesiosaur genera
* Timeline of plesiosaur research

References

External links

Libonectes morgani
Sachs Vertebrate Palaeontology Research.

Late Cretaceous plesiosaurs of North America
Elasmosaurids
Fossil taxa described in 1997
Taxa named by Kenneth Carpenter
Sauropterygian genera

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