[1] The genus name is derived from the Greek words stenos, "narrow"; rhynchos, "snout" and sauros, "lizard", while the specific name munozi is in recognition of Jorge Muñoz by discover and report the fossil.

[1] Fossils from the front of a snout of a plesiosaur were discovered in 2000 on the property of Jorge Muñoz, in Loma La Cabrera, near Villa de Leyva in Boyacá, Colombia, on grounds of marine origin dating from the Late Barremian age of the Cretaceous.

Then was made the excavation of the nearly complete skeleton between 2004 and 2005, in collaboration with the Fundación Colombiana de Geobiología ("Colombian Geobiology Foundation"), and the remains being then transferred to Bogotá, assigning the catalog number VL17052004-1, for preparation and study.

[1] The remains were found articulated mostly in the Segment C of the Arcillolitas Abigarradas Member of the Paja Formation, with kaolinitic argillite corresponding to an intertidal marine environment, with several specimens of ammonites or impressions of these in the rock matrix, including one inside the skull.

German paleontologist Oliver Hampe made an initial description of the specimen in 2005, classifying it as Brachauchenius sp., i.e. as an indeterminate species of this genus, previously only recorded in Upper Cretaceous sediments of the United States, and it constitutes the first reappearance of non-rhomaleosaurid pliosaurs after a hiatus between the Berriasian and Hauterivian.