A reconstruction of “grandfather turtle.” (Photo: Rainer Schoch)

It was hard to miss last week’s story about turtle evolution.  The story appeared at Smithsonian.com, LiveScience, and Science Magazine among others, with the original paper appearing in Nature.  CBC Radio did an interview with Dr. Hans-Dieter Sues, the Curator of Vertebrate Paleontology at the Smithsonian’s National Museum of Natural History in Washington.  Dr. Sues and Rainer R. Schoch, from the Natural History Museum in Stuttgart, Germany, studied the fossils (18 specimens) of the turtle ancestor which were found in Germany.  The animal, called Pappochelys (Greek for “grandfather turtle”), lived about 240 million years ago, during the Triassic.  When alive, the animal measured about 8 inches long, about the same size as a modern-day box turtle.

Pappochelys looked quite different than the turtles and tortoises of today, however. The animal had no shell, but it did have what appear to be the makings of one. Its ribs are broad and sturdy, and they fan out from the spine, a physiological set-up that the researchers suspect evolved not only for protection but also as a “bone ballast”—a way for the animal, which was likely aquatic or semiaquatic, to better control its buoyancy. That wasn’t the only hint of what would eventually become turtles’ trademark feature: Pappochelys also has a line of hard, almost shell-like bones along its belly.