A study published in Nature reveals the discovery of a transitional fossil, Pappochelys, which thrived in the period between 260 million-year-old reptilian beast, Eunotosaurus and 220 million-year-old Odontochelys. The filling of the void of 40 million years has rendered significant contribution to the history of evolution of the turtle shell. The 240 million years old fossil has been unearthed in a limestone quarry in Germany.

The researchers have nicknamed this transitional species as ‘grandfather turtle’, asserting that it is the ancestor of the turtle species and has evolved from reptiles. The researchers claim this 240 million years old fossil existed exactly between the transitions from the soft-backed animals to the hard-shelled turtles.

The researchers, after analyzing 18 fossil skeletons of this species, concluded the appearance of the ‘middle man’. The grandfather turtle has been described possessing broad and sturdy ribs and the fossil also reveals clear beginnings of a bony plate protecting its underside.

Hans Dieter Sue, a curator at the Smithsonian Museum of Natural History in DC and the study co-author, said, “It has real beginnings of the belly shell developing, little rib-like structures beginning to fuse together into larger plates and then ultimately making up the belly shell”.

Rainer R. Schoch, paleontologist at the Staatliches Museum für Naturkunde in Stuttgart and another study author, asserted that this kind of creature demonstrates that the evolution of today’s turtles was from their ancient lizard ancestors.

Schoch said the discovery of transitional creatures is the most important contribution that paleontology can make to the study of evolution.