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| Yaguarasaurus regiomontanus Rivera-Sylva, Longrich, Padilla-Gutierrez, Guzmán-Gutiérrez, Escalante-Hernández & González-Ávila, 2023 artwork: Luis Rey facebook.com/LuisRey5560 |
Abstract
The Mosasauridae underwent a major radiation early in the Late Cretaceous, with the subfamilies Plioplatecarpini and Tylosaurini appearing in the Turonian. Here we report an almost complete mosasaur skull assigned to the plioplatecarpine genus Yaguarasaurus. The specimen was discovered southwest of Vallecillo in the northeastern Mexico state of Nuevo Leon, about 80 km north of Monterrey, in a laminated limestone layer of the upper member of the Agua Nueva Formation (Upper Turonian - ?Lower Coniacian). The specimen is referred to as a new species, Yaguarasaurus regiomontanus. This is the first report of Yaguarasaurus from Mexico and the most complete of the Americas. At roughly 5 m in length, it is one of the earliest large mosasaurids. Along with Yaguarasaurus columbianus, Russellosaurus coheni, and an unnamed plioplatecarpine from Texas, it documents the rapid diversification and expansion of plioplatecarpines in the marine realm in the Turonian.
Systematic paleontology
Lepidosauria Haeckel 1866
Squamata Oppel, 1811.
Mosasauridae Gervais, 1853.
Plioplatecarpinae Dollo, 1884.
Yaguarasaurus Páramo, 1994
Yaguarasaurus regiomontanus sp. nov.
Conclusions:
A new plioplatecarpine mosasaurid, Yaguarasaurus regiomontanus, is reported from the Turonian-?Coniacian of Nuevo Leon, in Mexico. It closely resembles Yaguarasaurus columbianus from the Turonian of Columbia but exhibits derived features suggesting it may be more closely related to later plioplatecarpines. It is one of the earliest large mosasaurids and one of the first plioplatecarpines, documenting the initial radiation of mosasaurids in the Turonian following mid-Cretaceous extinctions in ...
Héctor E. Rivera-Sylva, Nicholas R. Longrich, José M. Padilla-Gutierrez, José Rubén Guzmán-Gutiérrez, Víctor M. Escalante-Hernández and José G. González-Ávila. 2023. A New Species of Yaguarasaurus (Mosasauridae: Plioplatecarpinae) from the Agua Nueva Formation (upper Turonian – ?Lower Coniacian) of Nuevo Leon, Mexico. Journal of South American Earth Sciences. In Press, 104694. DOI: 10.1016/j.jsames.2023.104694
