''Sulcusuchus'' is a genus of

polycotylid Polycotylidae is a family of plesiosaurs from the Cretaceous, a sister group to Leptocleididae. Polycotylids first appeared during the Albian stage of the Early Cretaceous, before becoming abundant and widespread during the early Late Cretaceous. ...

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 ...

from 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. Campanian sp ...

Argentina Argentina (), officially the Argentine Republic ( es, link=no, República Argentina), is a country in the southern half of South America. Argentina covers an area of , making it the second-largest country in South America after Brazil, th ...

Description

The

type species In 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 species that contains the biological type specimen ...

''Sulcusuchus erraini'' was named in 1990 by

Zulma Brandoni de Gasparini Zulma Nélida Brandoni de Gasparini (born 15 May 1944) is an Argentinian paleontologist and zoologist. She is known for discovering the fossils of the dinosaur ''Gasparinisaura'', which was named after her. Work Born in the city of La Plata, A ...

and Luis Spalletti. It was at first considered to have been a

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

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

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 several ...

, 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 capit ...

, 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. Campanian s ...

La Colonia Formation The La Colonia Formation is a geological 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.600-604 Originally thou ...

. 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 {{plesiosaur-stub

Description

See also

References