Anorith are not a particularly powerful pokemon, but have no natural predators, for their rocky exoskeleton provides little in the way of taste or nutrition for modern hunters. Conversely, their eight winglike fins give them unparalleled maneuverability in the water, from which few of the water pokemon they have taken to feeding on can escape. Their population has grown exponentially since their resurrection, albeit from a few released pokemon, and the gloomiest projections see them dominating the sea as they did in the Cambrian once more.
Whenever an invasive species of pokemon poses a threat to an area's ecosystem, it is standard practice to find them trainers, remove them to their natural habitat, or in extreme instances cull them to protect native species. The ethics of such a situation are considerably more complex when the pokemon in question has been extinct for eons. The researchers who have brought the Anorith back have advocated for a large area to be set aside as a wildlife reserve for them and other extinct pokemon, but finding such land would be difficult, and mixing and matching species from different eras into their own ecological niches no easier. Worse, even a steady trickle of escaped Anorith would be far more dangerous than the still numerically small number in the wild today.
At the moment, the novelty of the resurrected Anorith, despite their relative weakness in battle, has allowed adequate trainers to be found. Indeed, in Sinnoh demand can not be met by feral Anorith and their descendants, so trainers become fossil hunters in the Underground to get an Anorith of their own. It is hoped that a trainer will discover and science revive one of Anorith's predators in order to restore the ecosystem to equilibrium before Hoenn faces catastrophe, or the Anorith a second extinction.