A 240-million-year-old reptile with a skeletal precursor of a shell has been revealed as the grandfather of all turtles. Scientists have given it the moniker Pappochelys, meaning ‘grandfather turtle,’ in honor of its newly found position at the forefront of the turtles’ evolutionary lineage.
What the shell? Grandfather turtle was actually shell-less
Pappochelys, the lizard-like reptile found in a quarry in southern Germany, is now the oldest turtle fossil to date. Pappochelys is so old, the former turtle fossil who held the title, Odontochelys, would have roamed China over 20 million years after the grandfather turtle’s reign.
The bulky body of Pappochelys has clued in scientists about the origin and evolution of turtles. Whereas Odontochelys had a shell-like structure, Pappochelys had only a skeletal structure that would only later form into the modern turtle’s shell, called a carapace. Scientists believe the Triassic Period reptile had a combination of physical features from its own lizard-like ancestors and the soon-to-be modern day turtles, seen especially in the fossil’s skull.
This revelation suggests our turtles now are more closely related to snakes and lizards, rather than previous studies’ positions that they were descendants of birds and dinosaurs.
The Grandfather Turtle is the Missing Link in Turtle Evolution
Paleontologist Rainer Schoch of the State Museum of Natural History Stuttgart in Germany believes that Pappochelys is the missing link between lizards and turtles. The reptile’s age and the fact that it is the oldest fossil is one piece of evidence, but the greater reason is because the reptile’s anatomy is a more primitive version of our modern day turtles.
The age and anatomy of Pappochelys has made it clear to Schoch and other researchers that it is a transitional creature, one that bridges the evolutionary gap between its lizard ancestors and its turtle descendants. These creatures are an important contribution to science in the study of evolution according to Schoch. They can reveal how specific features, such as the turtle’s carapace, evolved over millions of years.
Lizard-Turtle: What Pappochelys Looked Like
Evidence from the 18 fossil skeletons of the species, allow researchers a picture of what Pappochelys may have looked like. The species was a mutant combination of lizard and turtle features, particular seen in the skull for the latter. Instead of the typical turtle beak we know today, Pappochelys had a lizard-like skull filled with many peg-like teeth. He used these teeth to eat insects, and it had a cannibalistic streak as it feasted on other smaller lizards.
The grandfather turtle had a broad trunk and thick bones had already started to fuse together in some areas around the belly, says co-author of the study Hans-Dieter Sues. The paleontologist from the Smithsonian Institution’s National Museum of Natural History remarked that this bone fusion was one of the first evolutionary steps in the turtle’s journey of acquiring its iconic shell.
Pappochelys also featured more features from its lizard ancestors, including a long tail, which it used to swim through the water while its legs were mainly used for steering away from predators. Although the Pappochelys predated dinosaurs by 10 million years, it still had to beware of its natural predators that waited in the water, like Mastodonsaurus and that lurked on the land, like Batrachotomus.
But even without the hard shell of its descendants, somehow Pappochelys managed to survive long enough to become known as the grandfather turtle to all modern day turtles.
