''Fluvionectes'' (meaning "river swimmer", from both Latin and Greek) is a genus of elasmosaurid plesiosaur found in the

Dinosaur Park Formation The Dinosaur Park Formation is the uppermost member of the Belly River Group (also known as the Judith River Group), a major geologic unit in southern Alberta. It was deposited during the Campanian stage of the Late Cretaceous, between about 7 ...

Alberta Alberta ( ) is one of the thirteen provinces and territories of Canada. It is part of Western Canada and is one of the three prairie provinces. Alberta is bordered by British Columbia to the west, Saskatchewan to the east, the Northwest Ter ...

Canada Canada is a country in North America. Its ten provinces and three territories extend from the Atlantic Ocean to the Pacific Ocean and northward into the Arctic Ocean, covering over , making it the world's second-largest country by tota ...

. It is known from a

holotype A holotype is a single physical example (or illustration) of an organism, known to have been used when the species (or lower-ranked taxon) was formally described. It is either the single such physical example (or illustration) or one of seve ...

, which includes parts of the trunk area, and from a much larger specimen referred to this taxon.

Description

The holotype of ''Fluvionectes'' reached long and weighed . A much larger specimen indicates that this taxon may have reached in maximum body length.

Classification

The describers placed ''Fluvionectes'' in the Elasmosauridae, in a clade with ''

Albertonectes ''Albertonectes'' is an extinct genus of elasmosaurid plesiosaur known from the Late Cretaceous (middle upper Campanian stage) Bearpaw Formation of Alberta, Canada. It contains a single species, ''Albertonectes vanderveldei''. ''Albertonecte ...

'', ''

Nakonanectes ''Nakonanectes bradti'' is an elasmosaurid plesiosaur of the late Cretaceous found in 2010 the state of Montana in the United States. It is one of the most recently known elasmosaurids to have lived in North America. Unlike other elasmosaurids ...

'', ''

Styxosaurus ''Styxosaurus'' is a genus of plesiosaur of the family Elasmosauridae. ''Styxosaurus'' lived during the Campanian age of the Cretaceous period. Two species are known: ''S. snowii'' and ''S. browni''. Description ''Styxosaurus'' was a large p ...

'', and ''

Terminonatator ''Terminonatator'' (meaning "last swimmer") is a genus of elasmosaurid plesiosaur from the Late Cretaceous of Saskatchewan, Canada. It is known from a skull and partial skeleton from a young adult, found in the Campanian-age Bearpaw Fo ...

'', which by definition places it in the Elasmosaurinae subfamily.

Paleobiology

''Fluvionectes'' appears to have been a

freshwater Fresh water or freshwater is any naturally occurring liquid or frozen water containing low concentrations of dissolved salts and other total dissolved solids. Although the term specifically excludes seawater and brackish water, it does in ...

(and possibly

brackish water Brackish water, sometimes termed brack water, is water occurring in a natural environment that has more salinity than freshwater, but not as much as seawater. It may result from mixing seawater (salt water) and fresh water together, as in estuari ...

) animal based on its discovery from a non-marine to paralic sedimentary unit. This is significantly different in contrast to most elasmosaurs which were oceanic.

References

Elasmosaurids Plesiosaurs Campanian genera Late Cretaceous reptiles of North America Cretaceous Alberta Paleontology in Alberta Fossil taxa described in 2021 Sauropterygian genera {{plesiosaur-stub