Mosasaurus is a genus of mosasaur, giant aquatic lizards that roamed the seas of the Late Cretaceous period. Mosasaurus has been found in parts of Europe and North America. While no Mosasaurus fossils are known from Hell Creek, it was alive at the end of the Maastricthian and lived in the neighboring Western Interior Seaway, so it's presence on the Hell Creek coast is perfectly plausible.

Background Information

Mosasaurus was one of the first mosasaurs to be discovered. They were very robust compared to other large mosasaurids as well as more robust skulls implying a stronger bite. They were believed to feed on various marine life including ammonites, sea turtles, hesperornithids, plesiosaurians, and even other mosasaurids as it was a highly aggressive hunter.

Physical AppearanceEdit

Mosasaurus is dark gray with a lighter underbelly and subtle striping on the sides. This coloration, with a dark top and lighter belly, is common to aquatic animals, namely sharks and dolphins.

Mosasaurs are known to have had shark-like tail flukes, used for propulsion. Saurian's Mosasaurus has a forked tongue, likely because its closest living relatives, monitor lizards and Gila monsters, do.

In SaurianEdit

Mosasaurus appears in the game. Mosasaurus was added for a particular function: to keep the player from swimming out too far into the ocean. If the player goes out too far, they will be eaten by the Mosasaurus, preventing them from reaching the edge of Saurian's map.[1] Mosasaurus' only other function in the game is that it is possible to find one beached.

Behind the ScenesEdit

The first design by Alex "Doc" Lewko depicted it as having a color scheme similar to most depictions following the study "Skin pigmentation provides evidence of convergent melanism in extinct marine reptiles" by Johan Lindgren et al. with the upper body being black and the underbelly being white. The body of this design was slender and serpentine-like most depictions of Mosasaurus.

The Mosasaurus saw a later-now scrapped design-by RJ Palmer. Palmer's design was bulkier and shorter with a dorsal fin. Also worth noting, was that the coloration of the Palmer designs Mosasaurus were more vibrant than what the findings by Lindgren et al. suggests. The most commonly seen color of Palmer's colorations being a brown with a spotted pattern with vertical lines. The reason why the colorations did not reflect the 2014 findings was because the concepts were done a year before in 2013.[2] Parker has stated that these designs of the Mosasaurus were not temporary and the game developers were seeking for more options before settling on a final design.[3]

Indeed, Mosasaurus later received a third design and model in 2017. RJ Palmer created the concept art for this design and was modeled by Jake Baardse under the guidance of paleontologist Nathan Van Vranken.[1]

It is stated that the Mosasaurus in game is impossible to kill.



  1. 1.0 1.1 1.2 1.3 Tomozasaurus. (January 19, 2017) Saurian DevLog #12 – Maastrichtian Lurker Shark. Saurian Website.
  2. Comments on Saurian Facebook Page.
    Brian Choo: Dig that mosasaur! - although the colouration may be a little over the top based on Lindgren et al.'s report on mosasaur fossil pigment (Nature 506, 484–488)
    Saurian: We agree, these concepts were done before said publication.
  3. Mosasaurus 001. ModDB. Retrieved September 11, 2016