Western Interior Seaway Protostegid

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* Other Fauna/Minor#Western Interior Seaway Protostegid

## ProtostegidIndeterminate species

Present on Prehistoric Planet is an **unnamed protostegid**, simply identified as a "giant, two-tonne turtle" on the show, that lived in the Western Interior Seaway at least 68 - 66 million years ago, during the Maastrichtian stage of the Late Cretaceous Period.

## Description

While this unidentified protostegid appears to be based on *Archelon ischyros*, the largest turtle to ever live, that species has already gone extinct 74 million years ago, during the Campanian Stage of the Late Cretaceous Period, so this leatherback turtle-esque creature might be another indeterminate, undescribed species of turtle. One suggestion is that this is *Pneumatoarthrus peloreus*, though this is unlikely given how *Pneumatoarthrus* is from Appalachia (the eastern half of the North American continent) and not Laramidia (the western side of North America, where *T. rex* resided in), and even if it also lived elsewhere, it appears to have died out 68 million years ago, just when *T. rex* first appeared.

## Appearance

In the first segment of Coasts, a *Tyrannosaurus* and his five chicks swim through a shallow sea to reach an offshore island. Some turtles can be seen swimming in the water, animals that would normally be hunted down by mosasaurs. Upon seeing the *T. rex* family, however, one mosasaur turns around to go after them instead. When the family finally escapes the sea and comes up onto dry land, the adult *T. rex* turns around to face the sea, and realizes that one of his five hatchlings got snapped up by the mosasaur pursuing them. With nothing more to be done about that, he turns to the smell that drew his attention to the offshore island.

***“ The island offers safety and the promise of food. Giant, two-tonne turtles are here to nest. But this is the one that has drawn him here. It's dead, and the tyrannosaur has smelt its rotting body. If he can just get to the underbelly, he will have over two thousand pounds of easy meat. ”***

― **David Attenborough**, *Coasts*
Ignoring the giant turtles crawling around, having arrived to the beach to lay their eggs, the *T. rex* walks to an already-dead turtle, turns it over, and crushes through its belly with his five-ton bite force. When his chicks try to get a taste, he drives them off with a growl, intending for them to learn to hunt for food on their own. The four surviving juveniles at first simply run around the beach, even playing around and riding a giant turtle at one point.

***“ But as the evening approaches, things start to change. Baby turtles are beginning to hatch from the sand, and rush down to the sea. ”***

― **David Attenborough**, *Coasts*
As evening approaches, the turtles eggs buried in the sand hatch, and the young turtles make their way to the sea. One young tyrannosaur at first plays around with these turtles, stomping some of them into the sand, and getting scared off by the waves as they take a turtle hatchling into the sea. Their parent still refuses to share the dead turtle he's eating, so one of the juveniles decides to go after a baby turtle, only to be fought off by one of its siblings, which steals and eats the baby turtle for itself, prompting in a game of chase. The segment ends with more of the newly-hatched turtles getting swept by the waves into the sea.