''Libonectes'' is an extinct genus of

sauropterygia Sauropterygia ("lizard flippers") is an extinct taxon of diverse, aquatic reptiles that developed from terrestrial ancestors soon after the end-Permian extinction and flourished during the Triassic before all except for the Plesiosauria bec ...

n reptile belonging to the plesiosaur order. It is known from specimens found in the

Britton Formation The Britton Formation is a geologic formation deposited during the Middle Cenomanian to the Early Turonian ages of the Late Cretaceous in modern-day East Texas. It forms the lower half of the Eagle Ford Group in the northern portion of East ...

Texas Texas (, ; Spanish language, Spanish: ''Texas'', ''Tejas'') is a state in the South Central United States, South Central region of the United States. At 268,596 square miles (695,662 km2), and with more than 29.1 million residents in 2 ...

(USA) and the Akrabou Formation of

Morocco Morocco (),, ) officially the Kingdom of Morocco, is the westernmost country in the Maghreb region of North Africa. It overlooks the Mediterranean Sea to the north and the Atlantic Ocean to the west, and has land borders with Algeria ...

, which have been dated to the lower

Turonian The Turonian is, in the ICS' geologic timescale, the second age in the Late Cretaceous Epoch, or a stage in the Upper Cretaceous Series. It spans the time between 93.9 ± 0.8 Ma and 89.8 ± 1 Ma (million years ago). The Turonian is preceded ...

stage of the late

Cretaceous The Cretaceous ( ) is a geological period that lasted from about 145 to 66 million years ago (Mya). It is the third and final period of the Mesozoic Era, as well as the longest. At around 79 million years, it is the longest geological period of ...

period.

Nomenclature

The

prefix A prefix is an affix which is placed before the stem of a word. Adding it to the beginning of one word changes it into another word. For example, when the prefix ''un-'' is added to the word ''happy'', it creates the word ''unhappy''. Particu ...

"''libo''" comes from

Greek Greek may refer to: Greece Anything of, from, or related to Greece, a country in Southern Europe: *Greeks, an ethnic group. *Greek language, a branch of the Indo-European language family. **Proto-Greek language, the assumed last common ancestor ...

, and means "southern," translated to

English English usually refers to: * English language * English people English may also refer to: Peoples, culture, and language * ''English'', an adjective for something of, from, or related to England ** English national id ...

. "''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 In taxonomy, binomial nomenclature ("two-term naming system"), also called nomenclature ("two-name naming system") or binary nomenclature, is a formal system of naming species of living things by giving each a name composed of two parts, bot ...

Description

The animal was very similar to the related ''

Thalassomedon ''Thalassomedon'' (from Greek, ''thalassa'', "sea" and Greek, ''medon'', "lord" or "ruler", meaning "sea lord") is a genus of plesiosaur, named by Welles in 1943. Description ''Thalassomedon'' is among the largest elasmosaurids, with a total ...

'', 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 In biology, a type is a particular specimen (or in some cases a group of specimens) of an organism to which the scientific name of that organism is formally attached. In other words, a type is an example that serves to anchor or centralizes the ...

, which also contains the neck and

gastrolith A gastrolith, also called a stomach stone or gizzard stone, is a rock held inside a gastrointestinal tract. Gastroliths in some species are retained in the muscular gizzard and used to grind food in animals lacking suitable grinding teeth. In oth ...

s, 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

, but a 2017 redescription of the material recognized it as a junior synonym of ''L. morgani''.

Feeding Habits

The possible

carnivorous A carnivore , or meat-eater (Latin, ''caro'', genitive ''carnis'', meaning meat or "flesh" and ''vorare'' meaning "to devour"), is an animal or plant whose food and energy requirements derive from animal tissues (mainly muscle, fat and other ...

nature of ''Libonectes'' is suggested by its dental layout, however, the presence of

gastroliths A gastrolith, also called a stomach stone or gizzard stone, is a rock held inside a gastrointestinal tract. Gastroliths in some species are retained in the muscular gizzard and used to grind food in animals lacking suitable grinding teeth. In othe ...

inside some known fossils feasibly indicates an

omnivorous An omnivore () is an animal that has the ability to eat and survive on both plant and animal matter. Obtaining energy and nutrients from plant and animal matter, omnivores digest carbohydrates, protein, fat, and fiber, and metabolize the nut ...

lifestyle (though

paleontological Paleontology (), also spelled palaeontology or palæontology, is the scientific study of life that existed prior to, and sometimes including, the start of the Holocene epoch (roughly 11,700 years before present). It includes the study of fossi ...

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 Ammonoids are a group of extinct marine mollusc animals in the subclass Ammonoidea of the class Cephalopoda. These molluscs, commonly referred to as ammonites, are more closely related to living coleoids (i.e., octopuses, squid and cuttle ...

, 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

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 {{plesiosaur-stub

Nomenclature

Description

Feeding Habits

See also

References

External links