for National Geographic News
Fossils of the earliest known swimming turtles have been uncovered on an island in northwest Britain, scientists reported today.
The fossils of the previously unknown species suggest turtles first took to water during the Middle Jurassic period (180 to 160 million years ago).
Four crushed but intact skeletons had been found along with the remains of two other specimens, in a single slab of rock in 2004 on Scotland's Isle of Skye. Since then, researchers have painstakingly freed the fossils.
The fossils belonged to a pond turtle, Eileanchelys waldmani, which bridges the evolutionary gap between primitive land turtles and modern aquatic turtles.
Turtles first appeared in the Triassic period some 210 million years ago. They were exclusively land creatures, said study team member Jérémy Anquetin, a French Ph.D. student at the Natural History Museum in London.
These earliest turtles were heavy, lumbering creatures armed with thick shells and protective spikes, he said.
But the new fossil turtle had a domed, tortoise-like shell measuring up to 11.8 inches (30 centimeters) long and it was much more delicately built.
"It's light framed, just like an aquatic turtle," Anquetin said.
"Until the discovery of Eileanchelys, we thought that adaptation to aquatic habitat might have appeared among primitive turtles, but we had no fossil evidence of that," he added.
"Now we know for sure that there were aquatic turtles around 164 million years ago," Anquetin said.
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