Libonectes

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title: "Libonectes" type: doc version: 1 created: 2026-02-28 author: "Wikipedia contributors" status: active scope: public tags: ["late-cretaceous-plesiosaurs-of-north-america", "elasmosauridae", "fossil-taxa-described-in-1997", "taxa-named-by-kenneth-carpenter", "sauropterygian-genera"] description: "Extinct genus of reptiles" topic_path: "general/late-cretaceous-plesiosaurs-of-north-america" source: "https://en.wikipedia.org/wiki/Libonectes" license: "CC BY-SA 4.0" wikipedia_page_id: 0 wikipedia_revision_id: 0

::summary Extinct genus of reptiles ::

|fossil_range = Late Cretaceous, |image = Libonectes atlasense skull.jpg |image_caption = Skull SMNK PAL 3978 |parent_authority = Carpenter, 1997 |authority = (Welles, 1949) [originally Elasmosaurus] |taxon = Libonectes morgani |synonyms =

• Elasmosaurus morgani Welles, 1949
• Libonectes atlasense Buchy, 2005 ::figure[src="https://upload.wikimedia.org/wikipedia/commons/5/58/Libonectes_skull.jpg" caption="Holotype skull of ''Libonectes morgani''"] ::

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

::figure[src="https://upload.wikimedia.org/wikipedia/commons/2/22/New_Libonectes.jpg" caption="url-status=dead}}"] ::

Description

Libonectes was a medium-sized plesiosaur, with the complete specimen (SMNK-PAL 3978) measuring 7.2 m long. The type specimen belonged to an individual with a neck measuring 5.06 m long. The animal was very similar to the related Thalassomedon, though the structure of the neck vertebrae was 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 type specimen of L. morgani contains the best preserved elasmosaurid skull known as well as gastroliths. A shoulder girdle and flippers were also found but were apparently discarded at some point atter 1962, along with the rear fourteen neck vertebrae of which only forty-eight remain.

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

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.

References

References

1. "Libonectes dinosaur".
2. "Libonectes morgani".
3. Welles, Samuel. (1949). "A new elasmosaur from the Eagle Ford Shale of Texas". Fondren Science Series.
4. (2016). "A Small Body Sized Non-Aristonectine Elasmosaurid (Sauropterygia, Plesiosauria) from the Late Cretaceous of Patagonia with Comments on the Relationships of the Patagonian and Antarctic Elasmosaurids". Ameghiniana.
5. Carpenter, K. (1999). "Revision of North American elasmosaurs from the Cretaceous of the western interior." ''Paludicola'', '''2'''(2): 148-173.
6. (2017). "Redescription of the elasmosaurid plesiosaurian ''Libonectes atlasense'' from the Upper Cretaceous of Morocco". Cretaceous Research.
7. (2018-07-22). "Diet and senses".
8. (2013-04-22). "A biomechanical analysis of the skull and adductor chamber muscles in the Late Cretaceous Plesiosaur Libonectes". Palaeontologia Electronica.

::callout[type=info title="Wikipedia Source"] This article was imported from Wikipedia and is available under the Creative Commons Attribution-ShareAlike 4.0 License. Content has been adapted to SurfDoc format. Original contributors can be found on the article history page. ::