soft-shelled

It came from a soft-shelled turtle, or trionychid, which researchers think was the animal responsible for the punting tracks.

Describing the Jordan, she writes, “These waters fuel the tamarisk and the rhododendron blossoming on the riverbanks. . . . These waters host catfish and carp and bream, tiny mollusks and soft-shelled turtles.”

The earliest dinosaurs laid soft-shelled eggs, paleontologists say.

A new chemical analysis of a more than 200-million-year-old fossilized egg from Patagonia—and a clutch of more recent eggs from Mongolia, found in the Gobi Desert—revealed a thin film matching the characteristics of modern soft-shelled eggs.

They are the only soft-shelled sea turtles.