Protostega ('first roof') is an extinct genus of marine turtle containing a single species, Protostega gigas. Its fossil remains have been found in the Smoky Hill Chalk formation of western Kansas (Hesperornis zone, dated to 83.5 million years ago) and time-equivalent beds of the Mooreville Chalk Formation of Alabama. Fossil specimens of this species were first collected in 1871, and named by Edward Drinker Cope in 1872. With a length of 3 metres (9.8 ft), it is the second-largest sea turtle that ever lived, second only to the giant Archelon, and the third-largest turtle of all time behind Archelon and Stupendemys.
In the game
Protostega is unlocked by beating its battle event. Once unlocked, it can be purchased for 2200 DNA in the Creature Market.