The species, known as Rafetus swinhoei, was once common in northern Vietnam’s Red River Delta but was hunted down in the 1970s and 1980s. Cu Rua’s death left just three known specimens — a couple in a zoo in Suzhou, China, and one turtle in Dong Mo Lake, outside Hanoi, whose sex has not been revealed.
The Suzhou turtles have produced no offspring, Tim McCormack, the program director of the Asian Turtle Program, a conservation group based in Hanoi, wrote last April. But he added that a fourth member of the species had been found in Xuan Khanh Lake, outside Hanoi, fueling hopes that wild Rafetus swinhoei could be brought together for captive breeding.
A few months later, Mr. McCormack wrote that the program had potentially found a second turtle of the same species in Dong Mo Lake, but that more investigation was needed to confirm the discovery. He said on Wednesday that a “species recovery” alliance, including Vietnamese officials and international wildlife advocacy groups, was working on a plan to capture known members of the species, determine their sex and possibly breed them.
“Finding the second animal has got people excited in the species again, and we believe it can be saved if we can bring them together,” Mr. McCormack said in an email.
After Cu Rua’s death, the corpse was kept in cold storage for weeks at the Vietnam National Museum of Nature, at minus 15 degrees Celsius, as the authorities debated how best to preserve it.
“It is not simple to mummify the turtle, so intensive consideration is inevitable,” Nguyen Trung Minh, the museum’s director general, said in 2016. The government ultimately rejected traditional mummification techniques and opted to plastify the animal instead, with help from German experts.
The plastinated Cu Rua now shares a room in Ngoc Son Temple with an embalmed relative who died in 1967. It can now be safely displayed at room temperature, but to shield it from dust, mildew and sunlight, the authorities have placed it in a glass case.
Ngoc Son Temple sits on an island in Hoan Kiem Lake that is connected to shore by a footbridge. The lake is a short drive from Ho Chi Minh’s granite-and-marble mausoleum, which Kim Jong-un, the North Korean leader, visited this month after his failed summit meeting with President Trump.