The dead sea turtle that appeared in one scene being scavenged by the Eustreptospondylus. This was one of the largest turtles to live in Europe during the Jurassic Period, with a total shell length and width of close to a metre. Of course, it would be utterly dwarfed by the gargantuan sea turtles of the Late Cretaceous. It's not closely related to the sea turtles of the modern day.