New species of large early mosasaur discovered in Mexico

[Still Waters]

A new species of mosasaur that lived about 90 million years ago has been found in Mexico. The marine reptile was roughly 5.2 metres long, making it one of the earliest large mosasaurs.

Yaguarasaurus regiomontanus is a member of Mosasauridae, a group of extinct marine reptiles that lived underwater while the dinosaurs ruled on land. Mosasaurs were the ocean’s top predators during the Late Cretaceous epoch (100.5–66 million years ago).

The new species lived during the Turonian stage (94–90 million years ago) of the Late Cretaceous.

https://cosmosmagazine.com/history/palaeontology/mexico-large-early-mosasaur/?

https://www.iflscience.com/90-million-year-old-fossil-of-fork-tongued-marine-monster-found-in-mexico-71793

The study is published in the Journal of South American Earth Sciences.

[Antigonos]

It lived in the southern extremity of the Western Interior Sea, which covered the western third of the US and  ran from the present day Arctic in the north all the way down to the Gulf in the south.

A great book on the prehistoric megafauna which inhabited it and its geologic history below. Part of the fantastic Life of the Past series.  There’s a more recent second edition as well, but I prefer the artwork on the cover of the first. It captures well the hazardous conditions of existence in the WIS. A giant ginsu shark preys on a young mosasaur.

Edited November 30, 2023 by Antigonos