She's about 80 years old. He's 100.
Breathless scientists watched this spring as the world's most endangered turtles successfully mated.
But the attempt to breed the species' last known female with the last known male in China has failed because the eggs didn't hatch, conservationists said Saturday.
The elderly pair can try again next year, part of a delicate attempt to keep the species alive.
Just four known Yangtze giant soft-shell turtles are left, and three are male.
The only female was found in a Chinese zoo just last year after a long and desperate search. She was quickly protected with a surveillance camera, a guard and bulletproof glass, and given the nickname “China Girl.”
A successful batch of baby turtles would be a welcome environmental win for China. The country's efforts to save its pandas are famous, but scientists have said about 40 percent of China's mammal species are endangered. Pollution and hunting almost erased the Yangtze turtles.
While more than half of the eggs seemed fertile, the embryos died early, a statement released Wednesday by the U.S.-based Turtle Survival Alliance said. The statement did not indicate whether the female turtle's age was a factor and instead blamed years of a low-calcium diet.
Besides the pair that mated, the only other known Yangtze turtles are two males in Vietnam.
The two Chinese turtles are preparing for another attempt next year.