It Is Not Extinct, It Never Existed

Turtles are at a much higher risk of extinction than many other vertebrates. About half of all 328 of their species are considered threatened. One of them -- or at least it was thought so -- is the Seychelles mud turtle Pelusios seychellensis. Just three specimens were collected at the end of the 19th century; they are still kept at the Natural History Museum in Vienna and the Zoological Museum in Hamburg.

Despite an intensive search for this species, which was declared extinct by the International Union for Conservation of Nature (IUCN), no further individuals were found. Consequently, it was assumed that the species had been eradicated.

former Pelusios seychellensis

Researchers of the Museum of Zoology at the Senckenberg Natural History Collections in Dresden now examined several mitochondrial loci of the original specimen from the museum in Vienna and discovered that these turtles in fact never represented a distinct species.

The genetic analyses showed that the Pelusios seychellensis individuals are actually members of another species, Pelusios castaneus. This species is widespread in West Africa and for a long time researchers thought that Pelusios seychellensis had to be a different species although the Seychelles turtles looked deceptively similar to the West African ones. 

The species Pelusios seychellensis has therefore never existed.