China's last female Yangtze giant softshell turtle. [Photo/Weibo]

China's last female Yangtze giant softshell turtle (Rafetus swinhoei) died on Saturday after an artificial insemination at the Suzhou Zoo in East China's Jiangsu province. Now, only three remain in the world.

An international research team carried out the fifth artificial insemination for the female turtle on Friday, but the animal did not recover from the procedure, even though researchers spent hours trying to save its life.

The dead female turtle is believed to be over 90 years old; Suzhou Zoo's male turtle is over 100 years old.

After the death, only three such animals remain in the world: One in the Suzhou Zoo, one in Dong Mo Lake west of Hanoi and one in Xuan Khanh Lake in Hanoi's outskirts.

The Yangtze giant softshell turtle is one of the world's largest known freshwater turtle species, and one of the world's 50 most threatened turtles.