So there was a single specimen ever seen - in 1862. Can we really be confident that this was a separate species and not some mutation of some other species?
> Coming upon a strange little stingray, a popular delicacy in Indonesia, Martens purchased the dead fish.
It was apparently fairly widely eaten and prized as food.
DNA tests would be unreliable. This ray has being swimming in formaldehyde for more than a thousand years; The DNA is damaged beyond recognizable and many morphological aspects could had been seriously damaged also (Specially if improperly fixed).
stingrays are specially sensitive to overfishing, but we need to remember that 90% of the ocean is still basically unknown, and the number of marine biologists expert in this family are... like four or so for the whole area?.
Though if they still have dna from that specimen it should be pretty easy to tell