Protostega Gigas Turtle Skull


Protostegidae is a family of extinct marine turtles that lived during the Cretaceous period. The family includes some of the largest sea turtles that ever existed. They had flattened bodies and had minimal shells.


Protostega Gigas Turtle Skull Replica measures 17.5 in. Protostega Gigas Turtle Skull is museum quality polyurethane cast. Made in USA. 2-part skull (separate cranium & jaw). Skull casting from The Denver Museum of Nature & Science. Our precise skull can be used as a teaching tool, museum skull exhibit, home décor skull, or office décor skull.

The Protostega gigas is a species of extinct sea turtle from 85 million years ago. Protostega (‘first roof’) is an extinct genus of sea 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 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.

Growing more than 10 feet long, Protostega was among the largest turtles to ever live. Unlike most turtles, whose shells are made of expanded and fused bones that form a relatively solid dome, widely spaced bones that looked more like the rafters of a roof held up Protostega’s leathery shell.

Though the shell design provided less protection, the lighter load combined with powerful, flipper-like front legs made Protostega a strong, inexhaustible swimmer. Females likely migrated hundreds of miles to lay eggs on sandy beaches, much like sea turtles do today.

Movement onshore, however, was difficult. An adult female Protostega may have weighed a ton or more, a hefty load to drag out of the ocean to lay eggs. But lay eggs on the beach they did by the dozens, a reproductive strategy of safety in numbers that helped at least a few survive to adulthood.

In fact, marine turtles were the only seagoing reptiles to escape extinction at the end of the Cretaceous, 65 million years ago.

A large and pointed head with a sharp beak and strong jaws probably helped the ancient turtles feed on slow-moving marine creatures such as jellyfish and shellfish as well as seaweed and floating carcasses much as their descendants do today.

Shark teeth embedded in Protostega bones housed at a museum in Chicago suggest the turtles were sometimes a meal themselves.

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Additional information

Weight 8 lbs
Dimensions 17.5 × 10.5 × 8.5 in
Protostega Gigas Turtle Facts:

Kingdom: Animalia
Phylum: Chordata
Class: Reptilia
Order: Testudines
Suborder: Cryptodira
Family: †Protostegidae
Genus: †Protostega
Type species: †Protostega gigas