(Photo: Bavarria/CC BY 2.0)

Some time ago, an 8-year-old named Kobus Snyman found some turtle bones on his father’s farm in South Africa. He wasn’t quite sure what he had, so he did what others might do in the same situation: he took the bones to a local museum.

The six-inch turtle specimen then made its way to scientists studying the ancient evolution of turtles and, specifically, how and why turtles evolved to wear protective shells. 

The researchers had seen other specimens of a 260-million-year-old species of turtle, but Snyman’s was the most complete they had access to, offering the scientists a rare look at a well-preserved Eunotosaurus africanus.

It also, they say, solved a mystery. That’s because scientists never quite understood why turtles had shells in the first place. Were they always for protection? It seemed like an awfully cumbersome way to go about it, and, as it turns out, the shells weren’t originally for protection at all.

Instead, they were for digging into the ground and burrowing, mostly to try and escape the blazing African sun. 

“Why the turtle shell evolved is a very Dr. Seuss like question and the answer seems pretty obvious—it was for protection,” says Tyler Lyson, who led the research. “But just like the bird feather did not initially evolve for flight—we now have early relatives of birds such as tyrannosaur dinosaurs with feathers that definitely were not flying—the earliest beginnings of the turtle shell was not for protection but rather for digging underground to escape the harsh South African environment where these early proto turtles lived.”

Sometimes your most important defenses, in other words, are unintended consequences.