Genus: Oneirosaurus PARAMO-FONESCA, NARVAEZ-RINCON & DENAVIDES-CARBRA, 2025
Etymology: Greek, oneiro, "dream", and Greek, saurus, "lizard." "Dream reptile" referring to the exceptional preservation of its delicate structures.

Species: caballeros PARAMO-FONESCA, NARVAEZ-RINCON & DENAVIDES-CARBRA, 2025
Etymology: In Honor of the late Mr. Jaime Caballero, who collected and reported the specimen. After his death his family handed teh specimen to the Museo Geologico Nacional Jose Royo y Gomez of the SCG.
= Mosasaurus nova PARAMO-FONESCA, 2012

Holotype: IGMp879524 (old IPN-2)

Locality: La Azufrada locality, Barancabermeja-Bucaramanga highway, 7°8'56"N, 73°18'24"W, Lebrija municipality, Santander, Colombia.

Horizon: Galembo Formation.

Biostratigraphy:

Age: Coniacian Stage, Lower Senonian Subepoch, Lower Gulf Epoch, Late Cretaceous.

Material: Nearly complete skull with articulaed mandible,lacking tis anterior end, adn disarticulated atlas.