Old Sea Turtle

By Annabelle Buck

Though the giant extinct sea turtle recently installed in Dinosaur Hall was a fast swimmer, it wasn’t fast enough. Visible bite marks on the underside of the fossilized body of the protostegid turtle create a vivid image of its gruesome death some 82 million years ago, when dinosaurs still ruled on land.

The protostegid turtle display, which includes three lovely casts of the same five-foot-diameter creature, tells the story of some of the largest sea turtles that ever lived. Each cast is set at a different angle so viewers can see how it swam through North America’s inland seas so many years ago.

Suspended from the ceiling of Dinosaur Hall, the turtles appear to glide through the air in endless circles, leaving an imaginary wake in their path. Visitors may conjure stories of their own about where it was headed and what it was doing when it met its demise.

Michael Triebold, owner of Triebold Paleontology which installed the display this fall, said the creature was probably killed by Tylosaurus, a large marine reptile closely related to modern lizards and snakes. The protostegid specimen now in our Dinosaur Hall was discovered in 2011 in western Kansas.

Tylosaurus probably killed it, crushed part of its head, part of its body,” said Triebold.


Protostegid turtles roamed the seas between 66 and 140 million years ago and were contemporaries of many species of dinosaurs, as well as the marine creatures one sees on a visit to Dinosaur Hall. The species was first described in 1872 by the famous Academy paleontologist Edward Drinker Cope.

The specimen Cope studied—which was only a small part of the animal’s skeleton—today resides in the Academy’s research collection of more than 18 million animals and plants. Protostegid turtles represent just one of the many discoveries of new species in the early years of paleontological research, studies which continue today at the nation’s oldest natural history museum.

The turtles’ addition to Dinosaur Hall enhances the Academy’s collection of ancient marine reptiles, which also includes mosasaurs, ichthyosaurs, bony fish, and a plesiosaur. Visitors will now be better able to visualize the diversity of North American inland seaways in the Cretaceous period.

“We want visitors to understand that the dinosaurs—defined as a specific group of reptiles—were surrounded by all sorts of other life,” said Dr. Ted Daeschler, the Academy’s vice president for collections and Drexel University associate professor. “We hope the protostegid sea turtles will give visitors a familiar form that they can imagine living during the Age of Dinosaurs.”

The turtles are a permanent installation to Dinosaur Hall. To plan your next visit to the Academy to see them,visit our website to see what other exhibits and activities are happening.

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