''Neustosaurus'' is a genus of marine crocodyliform from the

Early Cretaceous The Early Cretaceous ( geochronological name) or the Lower Cretaceous (chronostratigraphic name), is the earlier or lower of the two major divisions of the Cretaceous. It is usually considered to stretch from 145 Ma to 100.5 Ma. Geology Pro ...

. ''Neustosaurus'' was a carnivore that spent much, if not all, its life out at sea. No ''Neustosaurus'' eggs or nest have been discovered, so little is known of the reptile's lifecycle, unlike other large marine reptiles of the Mesozoic, such as

plesiosaur The Plesiosauria (; Greek: πλησίος, ''plesios'', meaning "near to" and ''sauros'', meaning "lizard") or plesiosaurs are an order or clade of extinct Mesozoic marine reptiles, belonging to the Sauropterygia. Plesiosaurs first appeared ...

s or ichthyosaurs which are known to give birth to live young out at sea. Where ''Neustosaurus'' mated, whether on land or at sea, is currently unknown. The name ''Neustosaurus'' means "Swimming lizard", and is derived from the Greek ''Neustos''- ("swimming") and -''sauros'' ("lizard").

History of discovery

There is only a single described species within ''Neustosaurus'', the type species ''N. gigondarum''. The holotype material consists of only the posterior of trunk and the tail, discovered in France, in Gigondas. However, identifying metriorhynchid genera from post-cranials is not easy,Fraas E. 1902. Die Meer-Krocodilier (Thalattosuchia) des oberen Jura unter specieller Berücksichtigung von ''Dacosaurus'' und ''Geosaurus''. ''Paleontographica'' 49: 1-72. as such until diagnostic material is discovered ''Neustosaurus'' is considered

nomen dubium In binomial nomenclature, a ''nomen dubium'' (Latin for "doubtful name", plural ''nomina dubia'') is a scientific name that is of unknown or doubtful application. Zoology In case of a ''nomen dubium'' it may be impossible to determine whether a s ...

.Buffetaut, E. 1982. Radiation évolutive, paléoécologie et biogéographie des Crocodiliens mésosuchienes. ''Mémoires Societé Geologique de France'' 142: 1–88. ''Neustosaurus'' has been considered a

junior synonym The Botanical and Zoological Codes of nomenclature treat the concept of synonymy differently. * In botanical nomenclature, a synonym is a scientific name that applies to a taxon that (now) goes by a different scientific name. For example, Linna ...

of either '' Dakosaurus'' and ''

Geosaurus ''Geosaurus'' is an extinct genus of marine crocodyliform within the family Metriorhynchidae, that lived during the Late Jurassic and the Early Cretaceous. ''Geosaurus'' was a carnivore that spent much, if not all, its life out at sea. No ''Geosa ...

'' Piveteau J. 1928. Le reptile de Gigondas et l’évolution des Métriorhynchidés. ''Annales de Paléontologie'' 17: 30-47. over the past 100 years. In 2009, Young and Andrade published a re-description of ''Geosaurus'', examining its relationships and the validity of species lumped into the genus. They concluded that ''Neustosaurus'' is a nomen dubium, but if new material was discovered it would be the senior synonym of ''

Cricosaurus ''Cricosaurus'' is an extinct genus of marine crocodyliforms of the Late Jurassic. belonging to the family Metriorhynchidae. The genus was established by Johann Andreas Wagner in 1858 for three skulls from the Tithonian (Late Jurassic) of German ...

''.Young, Mark T., and Marco Brandalise de Andrade, 2009. "What is ''Geosaurus''? Redescription of ''Geosaurus giganteus'' (Thalattosuchia: Metriorhynchidae) from the Upper Jurassic of Bayern, Germany." ''Zoological Journal of the Linnean Society'', 157: 551-585.

References

{{Taxonbar, from=Q5229790 Early Cretaceous crocodylomorphs Prehistoric pseudosuchian genera Prehistoric marine crocodylomorphs Prehistoric life of Europe