The skull of the prehistoric monster, which researchers from Mainz, Bonn and Los Angeles have now described for the first time, is two meters long.
Overall, the ichthyosaur that crossed the sea around 250 million years ago was around 17 meters tall and weighed 45 tons - a reptile the size of a sperm whale.
The research team named the newly discovered ichthyosaur Cymbospondylus youngorum in honor of the Young brewing family who sponsored the Nevada excavation.
The skull of the giant reptile was uncovered there in 2011 after work on the same site in 1998 uncovered parts of the ichthyosaur's vertebrae.
In the meantime, the researchers have simulated the ecosystem in which Cymbospondylus lived on the computer.
One of the findings is that the ichthyosaurs reached their enormous size much faster in the course of evolution than the whales, for example: They apparently benefited from an abundant food supply made up of ammonites and eel-like animals.
Link to the study