I admire you. Because we put together the technique over a couple of years it's been an evolutionary process. It would be very very difficult using our technique. They are too small to be ground away using any method I know of. In any case, from the pictures I've seen, they are exposed on the rock surfaces in a fairly 3 dimensional way anyway so you can get a feel for their shape.
All species go extinct in the end.
As to why species go extinct generally it's thought to be mostly bad luck. They happen to live in a sea that dries up for instance or are out-competed by a new arrival, perhaps wiped out by some strange disease or even hit by a meteorite during a large extinction event. If our creature had descendents still kicking around by then this is likely to have been the point at which they disappeared. That is all we have time for. Here is Dr Mark Sutton with a final word.