 Reginald Innes Pocock having studied specimens in the British Museum of Natural History disagreed in 1943, and placed all Sundaic elephants in the subspecies "Elephas maximus sumatrensis".In 1950, Paules Edward Pieris Deraniyagala described a subspecies "Elephas maximus borneensis", taking as his type an illustration in the National Geographical Magazine.In 2003, the debate was re-opened by a suggestion that the introduced Sulu elephants and the northeastern Borneo population might have descended from the now-extinct Javan elephant, which was named "Elephas maximus sondaicus" by Deraniyagala.