Wait a minute - these scientists were monitoring this population of Bramble Bay melomys, watched on as the ocean rose and killed them all, and did nothing? Nothing other that bitch to the newspapers, I mean?
Did it not occur to these science geniuses (genii?) to round them up and move them? Transport them to some sort of animal conservancy, where they could live out their lives is safety? THEY LEFT THEM TO DROWN?
As I thought in my head as I looked at your picture... "rat. Bastards... Rat bastards!"
Seriously, it didn't occur to any of them to take a couple of them home to save their lives? Is it that much more satisfying to them that they can say they whinged to the Powers That Be to no avail, instead of manning up and doing it themselves?
Pinpointing the extinction (or pseudoextinction) of a species requires a clear definition of that species. If it is to be declared extinct, the species in question must be uniquely distinguishable from any ancestor or daughter species, and from any other closely related species.
What is the uniquely distinguishable characteristic of this "mosaic-tailed rat?" A mosaic pattern on its tail? Come on, man!
As Wikipedia summarizes, isolated extinctions are quite common. And the source article (not linked in the post but available here) agrees, in its closing paragraph:
"Certainly, extinction and climatic change has gone hand in hand throughout the history of the world," he [John White, an ecologist from Deakin University in Australia, who was not involved in the study] said. "So, if this is one of the first, it is more than likely not going to be the last."
To which one should add, ... in the history of the world.