Mosasauria

Mosasauria
Temporal range: Cretaceous, 121–66 Ma [1][2][3][4]
Clockwise from top left: dolichosaurids (Dolichosaurus, Pontosaurus, and Tetrapodophis) and mosasauroids (Mosasaurus and Opetiosaurus)
Scientific classification Edit this classification
Domain: Eukaryota
Kingdom: Animalia
Phylum: Chordata
Class: Reptilia
Order: Squamata
Suborder: Anguimorpha
Clade: †Mosasauria
Marsh, 1880
Subgroups

Mosasauria is a clade of aquatic and semiaquatic squamates that lived during the Cretaceous period. Fossils belonging to the group have been found in all continents around the world. Early mosasaurians like dolichosaurs were small long-bodied lizards that inhabited nearshore coastal and freshwater environments; the Late Cretaceous saw the rise of large marine forms, the mosasaurids, which are the clade's best-known members.[4]

The clade is defined as all descendants of the last common ancestor of the mosasaur Mosasaurus hoffmannii and dolichosaurs Dolichosaurus, Coniasaurus, and Adriosaurus suessi.[5] Its placement within the squamate tree is highly controversial. Two prominent hypotheses include the varanoid hypothesis, which holds that mosasaurians are most closely related to monitor lizards, and the pythonomorph hypothesis, which argues for a sister relationship with snakes. A third ophidiomorph hypothesis argues that snakes are members of the Mosasauria as modern descendants of the dolichosaurs, while a fourth stem-scleroglossan hypothesis considers neither group to be related to the mosasaurians.[6]

  1. ^ Evans, S.E.; Manabe, M.; Noro Miuki; Isaji, S.; Yamaguchi, M. (2006). "A Long-Bodied Lizard From The Lower Cretaceous Of Japan". Palaeontology. 49 (5): 1143–1165. doi:10.1111/j.1475-4983.2006.00598.x. Archived from the original on 2022-05-20.
  2. ^ Evans, S.E. (2022). "The Origin and Early Diversification of Squamates". In Gower, D.J.; Zaher, H. (eds.). The Origin and Early Evolutionary History of Snakes. Cambridge University Press. pp. 5–110. doi:10.1017/9781108938891. ISBN 9781108938891.
  3. ^ Amiot, R.; Kusuhashi, N.; Saegusa, H.; Shibata, M.; Ikegami, N.; Shimojima, S.; Sonoda, T.; Fourel, F.; Ikeda, T.; Lécuyer, C.; Philippe, M.; Wang, X. (2021). "Paleoclimate and ecology of Cretaceous continental ecosystems of Japan inferred from the stable oxygen and carbon isotope compositions of vertebrate bioapatite". Journal of Asian Earth Sciences. 205: 104602. doi:10.1016/j.jseaes.2020.104602.
  4. ^ a b Mekarski, M.M. (2017). The Origin and Evolution of Aquatic Adaptations in Cretaceous Squamates (PhD). University of Alberta. doi:10.7939/R3KK94S2B. Archived from the original on 2023-10-13. Retrieved 2024-02-04.
  5. ^ Conrad, J.L. (2008). "Phylogeny And Systematics Of Squamata (Reptilia) Based On Morphology". Bulletin of the American Museum of Natural History. 310: 1–182. doi:10.1206/310.1. S2CID 85271610.
  6. ^ Augusta, B.G.; Zaher, H.; Polcyn, M.J.; Fiorillo, A.R.; Jacobs, L.L. (2022). "A Review of Non-Mosasaurid (Dolichosaur and Aigialosaur) Mosasaurians and Their Relationships to Snakes". In Gower, D.J.; Zaher, H. (eds.). The Origin and Early Evolutionary History of Snakes. Cambridge University Press. pp. 157–179. doi:10.1017/9781108938891. ISBN 9781108938891.