''Sulcusuchus'' is a genus of

polycotylid Polycotylidae is a family of plesiosaurs from the Cretaceous, a sister group to Leptocleididae. They are known as false pliosaurs. Polycotylids first appeared during the Albian stage of the Early Cretaceous, before becoming abundant and widesprea ...

plesiosaur The Plesiosauria or plesiosaurs are an Order (biology), order or clade of extinct Mesozoic marine reptiles, belonging to the Sauropterygia. Plesiosaurs first appeared in the latest Triassic Period (geology), Period, possibly in the Rhaetian st ...

from the Late Campanian to Early Maastrichtian of

Argentina Argentina, officially the Argentine Republic, is a country in the southern half of South America. It covers an area of , making it the List of South American countries by area, second-largest country in South America after Brazil, the fourt ...

Description

The

type species In International_Code_of_Zoological_Nomenclature, zoological nomenclature, a type species (''species typica'') is the species name with which the name of a genus or subgenus is considered to be permanently taxonomically associated, i.e., the spe ...

''Sulcusuchus erraini'' was named in 1990 by Zulma Brandoni de Gasparini and Luis Spalletti. It was at first considered to have been a

dyrosaurid Dyrosauridae is a family (biology), family of extinct neosuchian crocodyliforms that lived from the Campanian to the Eocene. Dyrosaurid fossils are globally distributed, having been found in Africa, Asia, Europe, North America and South America. ...

crocodile, hence its generic name: "trough crocodile". Its

holotype A holotype (Latin: ''holotypus'') is a single physical example (or illustration) of an organism used when the species (or lower-ranked taxon) was formally described. It is either the single such physical example (or illustration) or one of s ...

, MPEF 650, was at Jacobacci,

Río Negro Province Río Negro (, ''Black River'') is a province of Argentina, located in northern Patagonia. Neighboring provinces are from the south clockwise Chubut, Neuquén, Mendoza, La Pampa and Buenos Aires. To the east lies the Atlantic Ocean. Its cap ...

, uncovered in a layer of the late

Campanian The Campanian is the fifth of six ages of the Late Cretaceous epoch on the geologic timescale of the International Commission on Stratigraphy (ICS). In chronostratigraphy, it is the fifth of six stages in the Upper Cretaceous Series. Campa ...

La Colonia Formation The La Colonia Formation is a geological Formation (geology), formation in Argentina whose strata date back to the Late Cretaceous. Dinosaur remains are among the fossils that have been recovered from the formation.Weishampel et al., 2004, pp.600- ...

. It consists of a posterior left mandible fragment of about half a meter long with an associated jaw joint condyle of the skull, lower braincase, rear palate and middle snout fragment. The outer side of the mandible shows the trough, which would be exceptional for a crocodile. The mandibula and pterygoids show grooves that may have housed electro-sensitive organs.O’Gorman, J.P. & Gasparini, Z., 2013, "Revision of ''Sulcusuchus erraini'' (Sauropterygia, Polycotylidae) from the Upper Cretaceous of Patagonia, Argentina", ''Alcheringa'' 37: 161–174 The snout is very elongated and the pterygoids are fused.

References

Late Cretaceous plesiosaurs Campanian life Maastrichtian life Plesiosaurs of South America Cretaceous Argentina Fossils of Argentina Fossil taxa described in 1990 Taxa named by Zulma Brandoni de Gasparini Sauropterygian genera Polycotylidae {{plesiosaur-stub

Description

See also

References