Further discussion on the Eocene drowning of New Caledonia: Discordances from the point of view of zoology

We discuss the fauna of New Caledonia in the context of the prolonged submergence of Grande Terre until its re-emergence around 37 million years ago and whether the resulting fauna can be entirely explained by over-water dispersal. The current literature discussing the predominant neoendemism in New Caledonia is reviewed, questioning some of the discourse about how the fact that most animal and plant lineages are neoendemics should weigh in to disregard the fewer cases of paleoendemism (clades that have persisted and diversified in New Caledonia for over 37 million years). We argue that many of the examples used in the literature, selected for other purposes, were not chosen to test this particular hypothesis, but several old lineages of non-vagile animals show that a non-trivial number of clades have a history that predates the supposed emergence of New Caledonia. We conclude by posing the question of how much additional evidence should be needed to demonstrate a discordance between the geological history of the archipelago and the evolutionary history of its biota.