Purranisaurus is an extinct genus

Genus

In biology, a genus is a low-level taxonomic rank used in the biological classification of living and fossil organisms, which is an example of definition by genus and differentia...

 of marine crocodyliform from the Middle to Late Jurassic

Jurassic

The Jurassic is a geologic period and system that extends from about Mya to  Mya, that is, from the end of the Triassic to the beginning of the Cretaceous. The Jurassic constitutes the middle period of the Mesozoic era, also known as the age of reptiles. The start of the period is marked by...

 period of Chile

Chile

Chile ,officially the Republic of Chile , is a country in South America occupying a long, narrow coastal strip between the Andes mountains to the east and the Pacific Ocean to the west. It borders Peru to the north, Bolivia to the northeast, Argentina to the east, and the Drake Passage in the far...

 and Argentina

Argentina

Argentina , officially the Argentine Republic , is the second largest country in South America by land area, after Brazil. It is constituted as a federation of 23 provinces and an autonomous city, Buenos Aires...

. Rusconi originally regarded Purranisaurus potens (the type species

Type species

In biological nomenclature, a type species is both a concept and a practical system which is used in the classification and nomenclature of animals and plants. The value of a "type species" lies in the fact that it makes clear what is meant by a particular genus name. A type species is the species...

) to be a plesiosaur

Plesiosaur

Plesiosauroidea is an extinct clade of carnivorous plesiosaur marine reptiles. Plesiosauroids, are known from the Jurassic and Cretaceous Periods...

; however, Gasparini demonstrated that it was in fact a metriorhynchid

Metriorhynchidae

Metriorhynchidae is an extinct family of metriorhynchoid crocodyliforms from the Middle Jurassic to the Early Cretaceous period of Europe, North America and South America. Metriorhynchids are fully aquatic crocodyliforms. Their forelimbs were small and paddle-like, and unlike living crocodilians,...

 crocodyliform, and that may be a junior synonym of Metriorhynchus

Metriorhynchus

Metriorhynchus is an extinct genus of marine crocodyliform that lived in the oceans during the Middle to Late Jurassic. Metriorhynchus was named by the German palaeontologist Christian von Meyer in 1830. Metriorhynchus was a carnivore that spent much, if not all, its life out at sea...

.

Taxonomy and phylogeny

Recent phylogenetic analysis has shown that Purranisaurus is a distinct metriorhynchid genus. A subsequent study expanded the genus Purranisaurus to include Metriorhynchus casamiquelai and M. westermanni.

Valid species

• P. casamiquelai: Middle Jurassic of Chile (Callovian);
• P. westermanni: Middle Jurassic of Chile (Callovian). Although previously considered a junior synonym of P. casamiquelai, it has been revalidated;
• P. potens: End Jurassic of Argentina (Tithonian
  Tithonian
  In the geologic timescale the Tithonian is the latest age of the Late Jurassic epoch or the uppermost stage of the Upper Jurassic series. It spans the time between 150.8 ± 4 Ma and 145.5 ± 4 Ma...
  
  ).