Don’t Mock Turtles

Rudyard Kipling’s Just So stories set a genteel image of wild life in India and elsewhere. He introduced a new world to generations of children and his stories captured their imagination. He told how a leopard got its spots but not how the turtle got its shell.

Image This week there is newly discovered evidence about how turtles evolved and it is more unexpected than even Kipling would have envisaged. Tyler Lyson of Yale University has described fossils of early turtles from South Africa, 260 million years old.

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They reveal broadened ribs and an absence of intercostal muscles, features that went on to evolve over the next few million years to give fused ribs and vertebrae. These form the familiar shell of modern turtles.

Even stranger is the age of the South African fossils. They occurred eight million years BEFORE the biggest extinction event in the history of life, 252 million years ago (252Ma). That huge environmental catastrophe* caused 96% of living species to become extinct.

th-1Somehow the turtles survived. Maybe their primitive body armour protected them. And maybe Kipling would have had a gentler explanation.

[Current Biology; http://www.lunch.com

* do not confuse this 252Ma event with the smaller 65Ma event that killed off the dinosaurs.]

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