Genus
Valid Extinct

Oneirosaurus

Páramo Fonseca et al. 2025

Oneirosaurus is an extinct genus of plioplatecarpine mosasaurid known from the Late Cretaceous Galembo Formation of Colombia. The genus contains a single species, Oneirosaurus caballeroi, known from a well-preserved skull and mandible.

Temporal range
Triassic
Jurassic
Cretaceous
Paleogene
Neogene
252 201 145 66 0 Ma
PBDB occurrences
1
Group
Mosasaures
Carnivore aquatic Terrestrial
Oneirosaurus
click to enlarge
Oneirosaurus caballeroi holotype IGMp879524. A, photograph, drawing and interpretative scheme of the specimen without left mandibular ramus, in right lateral view. B, photograph, drawing and interpretative scheme of the specimen without left mandibular ramus, in left lateral view. Gray fill, sediment; pattern fill, broken bone surface; black, empty space. Scale bars: A = 50 mm; C-D = 30 mm. Abbreviations: an, angular; avc, anterior aperture of the vidian canal; bo, basioccipital; bptm, basipterygoid meniscus; bs, basisphenoid; c, coronoid; d, dentary; ec, ectopterygoid; ep, epipterygoid; ex, exoccipital; f, frontal; im, internal auditory meatus; is, interorbital septum; j, jugal; la, lacrimal; m, mandible; mx, maxilla; na, nasal; op, opisthotic-exoccipital; p, parietal; par, prearticular; pl, palatine; pmx, premaxilla; pof, postorbitofrontal; pr, prootic; prf, prefrontal; ps, parasphenoid; pt, pterygoid; pvc, posterior aperture of the vidian canal q; quadrate; rv, right vomer; sa, surangular; scp, sclerotic plate; smx, septomaxilla; so, supraoccipital; sp, splenial; stp, stapes; VII, IX-XII, exit of cranial nerves. © M. E. Páramo-Fonseca, J. A. Narváez-Rincón & C. D. Benavides-Cabra · CC BY 4.0 · Wikimedia
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Classification
Mosasauridae Family
›
Plioplatecarpinae Subfamily
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Oneirosaurus Genus
Fossil sites 1 geolocated sites
Distribution
Top countries
🇨🇴 Colombia
1
Geological formations
Galembo
1
Temporal distribution
Coniacian (89.8–85.7 Ma)
1
Species (1)
Oneirosaurus caballeroi 90 Ma
Images 2
Bibliography
Original description
M. E. Páramo Fonseca, J. A. Narváez Rincón, and C. D. Benavides-Cabra. 2025. Oneirosaurus caballeroi gen. et sp. nov., a new mosasaur from Colombia. Earth Sciences Research Journal 29(3):231-247 DOI ↗
Bibliography (1)
M. E. Páramo Fonseca, J. A. Narváez Rincón, and C. D. Benavides-Cabra. 2025. Oneirosaurus caballeroi gen. et sp. nov., a new mosasaur from Colombia. Earth Sciences Research Journal 29(3):231-247 DOI ↗