List of mosasaur genera

Tylosaurus proriger mounted skeleton in the Rocky Mountain Dinosaur Resource Center in Woodland Park, Colorado

This list of mosasaurs is a comprehensive listing of all genera that have ever been included in the family Mosasauridae or the parent clade Mosasauroidea, excluding purely vernacular terms. The list includes all commonly accepted genera, but also genera that are now considered invalid, doubtful ( nomen dubium ), or were not formally published ( nomen nudum ), as well as junior synonyms of more established names, and genera that are no longer considered mosasauroid. Non-mosasaurid mosasauroids shall be noted as such. The list currently includes 92 genera, out of which 58 are considered valid (47 mosasaurids and 10 other mosasauroids).

Scope and terminology

There is no official, canonical list of mosasaur genera but one of the most thorough attempts can be found on the "Pythonomorpha" section of Mikko Haaramo's Phylogeny Archive.

Naming conventions and terminology follow the International Code of Zoological Nomenclature. Technical terms used include:

• Junior synonym : A name which describes the same taxon as a previously published name. If two or more genera are formally designated and the type specimens are later assigned to the same genus, the first to be published (in chronological order) is the senior synonym, and all other instances are junior synonyms. Senior synonyms are generally used, except by special decision of the ICZN, but junior synonyms cannot be used again, even if deprecated. Junior synonymy is often subjective, unless the genera described were both based on the same type specimen.
• Nomen nudum (Latin for "naked name"): A name that has appeared in print but has not yet been formally published by the standards of the ICZN. Nomina nuda (the plural form) are invalid, and are therefore not italicized as a proper generic name would be. If the name is later formally published, that name is no longer a nomen nudum and will be italicized on this list. Often, the formally published name will differ from any nomina nuda that describe the same specimen. In this case, these nomina nuda will be deleted from this list in favor of the published name.
• Preoccupied name: A name that is formally published, but which has already been used for another taxon. This second use is invalid (as are all subsequent uses) and the name must be replaced. As preoccupied names are not valid generic names, they will also go unitalicized on this list.
• Nomen dubium (Latin for "dubious name"): A name describing a fossil with no unique diagnostic features.

Mosasaur genera

Genus Author(s) Year Status Age Location Notes Images Acteosaurus Meyer 1860 Valid Late Cretaceous Slovenia Its vertebral column resembles that of extant varanid lizards Adriosaurus Seeley 1881 Valid Late Cretaceous Croatia Slovenia The A. skrbinensis specimen preserves a phosphatic matter in its stomach area, likely remains of fish, which suggests it may have been piscivorous Aigialosaurus Kramberger 1892 Valid Late Cretaceous Croatia Has been suggested to be the oldest known member of the lineage that led to the larger mosasaurids Amphekepubis Mehl 1930 Dubious Late Cretaceous Mexico Possibly a junior synonym of Mosasaurus Amphorosteus Gibbs 1851 Dubious Late Cretaceous United States Only known from two, heavily weathered vertebrae Ancylocentrum Schmidt 1927 Jr. synonym N/A N/A Junior synonym of Prognathodon Angolasaurus Antunes 1964 Valid Late Cretaceous Angola Brazil? Niger? United States? Mostly similar to the related Platecarpus , but with a somewhat longer skull Aphanizocnemus Dal Sasso & Pinna 1997 Valid Late Cretaceous Lebanon Although commonly regarded as a dolichosaurid, a few analyses suggest it may be outside of that group Baptosaurus Marsh 1870 Jr. synonym N/A N/A Junior synonym of Halisaurus Baseodon Leidy 1865 Jr. synonym N/A N/A Junior synonym of Mosasaurus Batrachiosaurus Harlan 1839 Jr. synonym N/A N/A Junior synonym of Mosasaurus Bentiabasaurus Polcyn, Schulp & Gonçalves 2023 Valid Late Cretaceous Angola Discovered as a stomach content of an adult Prognathodon Brachysaurana Strand 1926 Jr. synonym N/A N/A Junior synonym of Prognathodon Brachysaurus Williston 1897 Preoccupied N/A N/A Preoccupied by a junior synonym of iguanian lizard genus Stenocercus ; [1] referred to replacement names Brachysaurana and Ancylocentrum, of which the latter has priority as such, although both names are synonyms of Prognathodon Carinodens Thurmond 1969 Valid Late Cretaceous Belgium Denmark Jordan Morocco Netherlands Russia Ukraine Closely related to Globidens , but can be distinguished by its compressed teeth Carsosaurus Kornhuber 1893 Valid Late Cretaceous Slovenia Preserves skin impressions and sternal cartilage Clidastes Cope 1868 Valid Late Cretaceous United States One of the earliest known hydropedal mosasaurs Compressidens Dollo 1924 Preoccupied N/A N/A Preoccupied by a tusk shell; later renamed Carinodens Coniasaurus Owen 1850 Valid Late Cretaceous Germany United Kingdom United States Only known from incomplete remains, but they are enough to tell that it had an elongated skull containing specialized dentition Dallasaurus Polcyn & Bell 2005 Valid Late Cretaceous United States Has been said to be a "missing link" uniting fully aquatic mosasaur taxa and their terrestrial ancestors Dolichosaurus Owen 1894 Valid Late Cretaceous United Kingdom Possessed an exceptionally long neck Dollosaurus Yakovlev 1905 Jr. synonym N/A N/A Junior synonym of Prognathodon Drepanodon Leidy 1856 Jr. synonym N/A N/A Junior synonym of Mosasaurus Ectenosaurus Russell 1967 Valid Late Cretaceous United States One of the few plioplatecarpines that was not exclusive to nearshore marine environments Edestosaurus Marsh 1871 Jr. synonym N/A N/A Junior synonym of Clidastes Eidolosaurus Nopcsa 1923 Valid Late Cretaceous Slovenia One of the oldest known mosasauroids Elliptonodon Emmons 1858 Jr. synonym N/A N/A Junior synonym of Tylosaurus Eonatator Bardet et al. 2005 Valid Late Cretaceous Colombia Sweden United States The type species was originally referred to Clidastes and Halisaurus Eremiasaurus LeBlanc et al. 2012 Valid Late Cretaceous Brazil Israel Morocco Characterised by its robust skull with pronounced heterodont dentition Gavialimimus Strong et al. 2020 Valid Late Cretaceous Angola? Morocco Unusually, its snout was elongated, convergent with the extant gharial, hence its genus name Globidens Gilmore 1912 Valid Late Cretaceous Angola Brazil Colombia Jordan Morocco Syria United States Known for its rounded teeth, an adaptation to crush shelled prey such as molluscs Gnathomortis Lively 2020 Valid Late Cretaceous United States Previously identified as a species of Prognathodon , but it has been found to be different enough from that taxon to receive its own genus Goronyosaurus Azzaroli et al. 1972 Valid Late Cretaceous Niger Nigeria Possessed straight teeth with rounded apices more well suited for smashing food Haasiasaurus Polcyn et al. 2003 Valid Late Cretaceous Palestine Possibly chimeric as all referred remains were not found in association [2] Hainosaurus Dollo 1885 Jr. synonym N/A N/A Junior synonym of Tylosaurus Halisaurus Marsh 1869 Valid Late Cretaceous Egypt Jordan? Morocco Peru? United States May have been a poor swimmer due to the lack of hyperphalangy as seen in more derived genera Harranasaurus Kaddumi 2009 Valid Late Cretaceous Jordan Only known from a single mandible Holcodus Gibbs 1851 Jr. synonym N/A N/A Junior synonym of Platecarpus Holosaurus Marsh 1880 Preoccupied N/A N/A Referred to Platecarpus Hydrosaurus Kornhuber 1873 Preoccupied N/A N/A Preoccupied by agamid lizard genus Hydrosaurus ; renamed Pontosaurus Igdamanosaurus Lingham-Soliar 1991 Valid Late Cretaceous Egypt Niger Its dentary was massively built, similar to Prognathodon and its relative Globidens Jormungandr Zietlow, Boyd & van Vranken 2023 Valid Late Cretaceous United States Shares features of its skeleton with both basal and derived mosasaurines Kaganaias Evans et al. 2006 Valid Early Cretaceous Japan The oldest and basalmost known dolichosaurid Kaikaifilu Otero et al. 2017 Valid Late Cretaceous Antarctica Potentially a tylosaurine, although some researchers consider this assignment problematic Khinjaria [3] Longrich et al. 2024 Valid Late Cretaceous Morocco May have probably hunted large prey items due to its large body size and blade-like teeth. Closely related to Goronyosaurus Kolposaurus Camp 1942 Preoccupied N/A N/A Preoccupied by a junior synonym of the unrelated Nothosaurus ; [4] referred to Plotosaurus Komensaurus Caldwell & Palci 2007 Valid Late Cretaceous Slovenia Before its formal description, it had been nicknamed the "Trieste aigialosaur" Kourisodon Nicholls & Meckert 2002 Valid Late Cretaceous Canada Japan Coexisted with several elasmosaurids, turtles, and other mosasaurs Lakumasaurus Novas et al. 2002 Jr. synonym N/A N/A Junior synonym of Taniwhasaurus Latoplatecarpus Konishi & Caldwell 2011 Valid Late Cretaceous Canada Russia United States One of the largest named plioplatecarpines Leiodon Owen 1841 Preoccupied N/A N/A Preoccupied by a fish; referred to Liodon Lesticodus Leidy 1859 Jr. synonym N/A N/A Junior synonym of Mosasaurus Lestosaurus Marsh 1872 Jr. synonym N/A N/A Junior synonym of Platecarpus Liodon Agassiz 1846 Dubious Late Cretaceous United Kingdom Several species have been referred to this genus, although they do not belong to a single taxon Macrosaurus Owen 1849 Jr. synonym N/A N/A Junior synonym of Mosasaurus Megapterygius [5] Konishi et al. 2023 Valid Late Cretaceous Japan The neural spines of its posterior dorsal vertebrae have an abrupt change in orientation, which would have supported a dolphin-like dorsal fin in life Mesoleptos Cornalia & Chiozza 1852 Valid Late Cretaceous Croatia Palestine Slovenia An early member of the Mosasauroidea Moanasaurus Wiffen 1980 Valid Late Cretaceous New Zealand One of the largest known mosasaurines Mosasaurus Conybeare 1822 Valid Late Cretaceous Antarctica Argentina Belgium Brazil Canada Jordan Morocco Netherlands Russia South Africa Turkey United States The first mosasaur genus ever named and described Nectoportheus Cope 1868 Jr. synonym N/A N/A Junior synonym of Mosasaurus Oneirosaurus [6] Páramo-Fonseca et al. 2025 Valid Late Cretaceous Colombia Known from a single, well-preserved skull Opetiosaurus Kornhuber 1901 Valid Late Cretaceous Croatia Has been suggested to be synonymous with Aigialosaurus , [7] but this was not supported by subsequent research [8] Oterognathus Dollo 1889 Jr. synonym N/A N/A Junior synonym of Plioplatecarpus Pannoniasaurus Makádi, Caldwell & Ősi 2012 Valid Late Cretaceous Hungary Lived in a freshwater habitat unlike other members of its family, which were marine predators Phosphorosaurus Dollo 1889 Valid Late Cretaceous Belgium Japan Had large eye sockets, which imply it would have hunted its prey in deep water or at night Platecarpus Cope 1869 Valid Late Cretaceous Australia? Belgium? United States One specimen is so well-preserved it shows that mosasaurs were powerful, agile swimmers Plesioplatecarpus Konishi & Caldwell 2011 Valid Late Cretaceous United States Six specimens are known to date Plesiotylosaurus Camp 1942 Valid Late Cretaceous United States Some traits of its skull are seemingly convergent with tylosaurine mosasaurs Plioplatecarpus Dollo 1882 Valid Late Cretaceous Canada Netherlands Sweden United States Lived in a broad range as suggested by its fossil record Plotosaurus Camp 1951 Valid Late Cretaceous United States Unusually, its overall morphology was more similar to that of ichthyosaurs than to other mosasaurs, which led to its quite derived position within the latter group Pluridens Lingham-Soliar 1998 Valid Late Cretaceous Morocco Niger Nigeria Some specimens preserve injuries to their jaws, which would indicate they may have engaged in intraspecific combat Pontosaurus Gorjanovic-Kramberger 1892 Valid Late Cretaceous Croatia Lebanon Two species are known Portunatasaurus Mekarski et al. 2019 Valid Late Cretaceous Croatia Has been used as a subject for the understanding on the evolution of mosasauroid limb morphology Primitivus Paparella et al. 2018 Valid Late Cretaceous Italy The first dolichosaurid named from Italy Proaigialosaurus Kuhn 1958 Valid Late Jurassic Germany Often regarded as an aigialosaurid, but it may have also been a pleurosaurid Prognathodon Dollo 1889 Valid Late Cretaceous Angola? Belgium Canada? Israel Jordan Netherlands? New Zealand? Spain Syria Ukraine United States? Possibly paraphyletic as most assigned species may not belong to this genus Prognathosaurus Williston 1897 Jr. synonym N/A N/A Junior synonym of Prognathodon Pterycollosaurus Dollo 1882 Jr. synonym N/A N/A Junior synonym of Mosasaurus Rhamphosaurus Cope 1872 Preoccupied N/A N/A Preoccupied by another lizard genus; referred to Tylosaurus Rhinosaurus Marsh 1872 Preoccupied N/A N/A Preoccupied; [9] referred to Tylosaurus Rikisaurus Wiffen 1990 Jr. synonym N/A N/A Junior synonym of Moanasaurus Rikkisaurus Bell et al. 1999 Lapsus calami N/A N/A Lapsus calami of Rikisaurus, a junior synonym of Moanasaurus Romeosaurus Palci et al. 2013 Valid Late Cretaceous Italy None of the described specimens has enough well-preserved postcranial material, making it somewhat difficult to make any good judgements of the genus' full anatomy Russellosaurus Polcyn & Bell 2005 Valid Late Cretaceous United States One of the oldest mosasaurs described from North America Sarabosaurus Polcyn et al. 2023 Valid Late Cretaceous United States Based on remains of a mature animal as indicated by its preserved growth rings Saurochampsa Wagler 1830 Jr. synonym N/A N/A Junior synonym of Mosasaurus Selmasaurus Wright & Shannon 1988 Valid Late Cretaceous United States Would have been unable to widen its jaws to attack large prey due to its uniquely akinetic skull Sironectes Cope 1840 Jr. synonym N/A N/A Junior synonym of Platecarpus Stelladens Longrich et al. 2023 Valid Late Cretaceous Morocco Named for its star-shaped teeth Taniwhasaurus Hector 1874 Valid Late Cretaceous Antarctica Japan? New Zealand South Africa? May have possessed an electro-sensitive organ in its snout foramina that was likely capable of detecting movements of prey underwater Tetrapodophis Martill et al. 2015 Valid Early Cretaceous Brazil Originally described as a basal snake but later often reinterpreted as a dolichosaurid Tethysaurus Bardet, Pereda-Suberbiola & Jalil 2003 Valid Late Cretaceous Morocco Exhibits a mixture of primitive and advanced features Thalassotitan Longrich et al. 2022 Valid Late Cretaceous Morocco Its discovery shows that mosasaurs evolved to be the apex predators in the Late Cretaceous oceans. Closely related to Prognathodon Tylosaurus Marsh 1872 Valid Late Cretaceous Angola Belgium Canada Democratic Republic of the Congo? France Morocco Sweden United States Some species are among the largest mosasaurs yet known Vallecillosaurus Smith & Buchy 2008 Valid Late Cretaceous Mexico One of the oldest mosasauroids ever described Xenodens Longrich et al. 2021 Valid Late Cretaceous Morocco One study considered this taxon a nomen dubium due to the lack of authenticity, [10] but this was refuted by the discovery of additional material and CT scans [11] Yaguarasaurus Páramo 1994 Valid Late Cretaceous Colombia Mexico The most completely known South American mosasaur during the time of its description

See also

• Mosasaur
• Platynota
• Aigialosaur

Notes

1. Stenocercus at Herpbreeder.com Archived April 29, 2007, at the Wayback Machine . Retrieved 12-03-2007.
2. Alessandro Palci, Michael W. Caldwell and Cesare A. Papazzoni (2013). "A new genus and subfamily of mosasaurs from the Upper Cretaceous of northern Italy". Journal of Vertebrate Paleontology. 33 (3): 599–612. doi:10.1080/02724634.2013.731024. hdl: 11380/941691 . S2CID   86646993.
3. Longrich, Nicholas R.; Polcyn, Michael J.; Jalil, Nour-Eddine; Pereda-Suberbiola, Xabier; Bardet, Nathalie (2024-03-01). "A bizarre new plioplatecarpine mosasaurid from the Maastrichtian of Morocco". Cretaceous Research . 160 105870. Bibcode:2024CrRes.16005870L. doi:10.1016/j.cretres.2024.105870. hdl: 1874/438706 . ISSN   0195-6671.
4. Sauropterygia at Paleofile.com. Retrieved 12-03-2007.
5. Konishi, Takuya; Ohara, Masaaki; Misaki, Akihiro; Matsuoka, Hiroshige; Street, Hallie P.; Caldwell, Michael W. (2023). "A new derived mosasaurine (Squamata: Mosasaurinae) from south-western Japan reveals unexpected postcranial diversity among hydropedal mosasaurs". Journal of Systematic Palaeontology. 21 (1). doi:10.1080/14772019.2023.2277921. ISSN   1477-2019.
6. Páramo-Fonseca, María Eurídice; Narváez-Rincón, José Alejandro; Benavides-Cabra, Cristian David (2025-10-29). "Oneirosaurus caballeroi gen. et sp. nov., a new mosasaur from Colombia". Earth Sciences Research Journal. 29 (3): 231–247. doi:10.15446/esrj.v29n3.117157 (inactive 2025-10-29). ISSN   2339-3459.
7. Dutchak, Alex R.; and Caldwell, Michael W. (2009)."A redescription of Aigialosaurus (= Opetiosaurus) bucchichi (Kornhuber, 1901) (Squamata: Aigialosauridae) with comments on mosasauroid systematics". Journal of Vertebrate Paleontology29 (2): 437-452.
8. Madzia, D., Cau, A. (2017). Inferring "weak spots" in phylogenetic trees: application to mosasauroid nomenclature Archived 2017-09-17 at the Wayback Machine . PeerJ 5:e3782
9. Edward Drinker Cope "On the structure of the Pythonomorpha". (1872) Proceedings of the Academy of Natural Sciences of Philadelphia, 24:140-141
10. Sharpe, Henry S.; Powers, Mark J.; Caldwell, Michael W. (2024-12-16). "Reassessment of Xenodens calminechari with a discussion of tooth morphology in mosasaurs". The Anatomical Record . doi: 10.1002/ar.25612 . ISSN   1932-8486. PMC   12239698 . PMID   39682068.
11. Longrich, N. R.; Bardet, N.; Jalil, N.-E.; Pereda-Suberbiola, X.; Schulp, A.; Ghamizi, M. (2025). "New Information on the Morphology and Tooth Replacement of Xenodens calminechari (Squamata: Mosasauridae), a Unique Mosasaurid from the Maastrichtian Phosphates of Morocco". Diversity. 17 (12) 819. doi: 10.3390/d17120819 .

References

• "Pythonomorpha – snake-like squamates". Mikko's Phylogeny Archive. Archived from the original on January 23, 2008.
• "Mosasauridae Translation and Pronunciation Guide (by Ben Creisler)". Dinosauria.com. Archived from the original on May 2, 2008.