“But there is not yet any scientific evidence to prove the turtle they found was truly a Rafetus swinhoei,” Duc said, adding that only a DNA test would settle the true species of the turtle once and for all.

On Wednesday, Cleveland Metroparks Zoo’s Asian Turtle Program’s Vietnam-based coordinator Doug Hendrie announced the discovery, saying it was “incredibly important” as the Rafetus swinhoei was one of the most endangered turtle species in the world. 

The zoo said besides the most recently discovered turtle, there were only three other living specimens of the species: two in China and one in Hanoi’s Sword Lake.   

Rafetus swinhoei occupies an important place in Vietnamese folk culture. 

According to local legend, the 15th century Emperor Le Loi was once given a magic sword by a fisherman. He used the sword to repel the Chinese Ming invaders. 

A day after victory, Le Loi was in a boat in Sword Lake - which was then known as Green Water Lake - when a giant turtle swam up and asked the king to return the sword to the Dragon King.      

Since then, the lake has been known as the Lake of the Returned Sword or Sword Lake for short. 

Nguyen Xuan Thuan, coordinator of the Asian Turtle Program’s Vietnamese turtle component, said his team started researching the Rafeus swinhoei five years ago and had since then conducted many interviews with residents living in the Red River area where the species was likely to exist. 

Last March, they discovered a turtle and three months later they managed to photograph it. Thuan said the turtle was between 50 and 60 centimeters in length. Local residents estimated weighed about 90 kilograms. 

Thuan said the world’s leading turtle expert Peter Prichard had confirmed the turtle was a Rafetus swinhoei.

But Duc said without a DNA test, the turtle needed to be compared to the one still living in Sword Lake before it could be conclusively identified as Rafetus swinhoei.

Reported by Quang Duan