Life of the Meridian Islands: Colossal Quadclaw

Over the last 15,000 years, the Meridian Islands have become colder, and their tall forest cover has been lost, replaced with low-growing bushes and occasional wind-stricken trees that grow in contorted and crooked ways as they fight against the cool wind and nightly hard freezes, even though the midday heats the land to an almost balmy 62 degrees Fahrenheit for several hours under the equatorial sun. Most of the islands are now grassland, and strict forest specialists have fared poorly against this environmental change. Even so, the islands remain milder and more comfortable than most any other landmass at this time, and still support unique and endemic species. Terracudas such as the large shadowstalker have adjusted with little issue to the more open terrain, as their primary prey the pitpocket still finds suitable food in the seeds, fungus, and herbs that still thrive in the more open landscape. In addition, newly cleared plains now attract flocks of grazing seraphs from off the sea - a very abundant new prey species for the native predators, which have survived with only slight physical changes, namely thicker pelts to insulate during the nights.

But an increase in grazing birds has brought problems to native grazers. For there is a group of animals which have lived on these islands for many millions of years, since before any birds or tribbats lost their flight, which are now in danger. It is not the growing cold, but the appearance of new competitors which now threatens the survival of the largest land arthropod ever to live upon Serina: the colossal quadclaw, a descendant of oceanic hermit crabs which now lives its entire life on dry land, and can weigh up to twenty-five pounds and grow to three feet across. Heavier-built than a coconut crab and with more erect legs better designed to bear its weight vertically, this gigantic and ancient species has filled a tortoise-like role on the Meridian islands for almost ten million years. It belongs to a lineage of completely terrestrial crabs, which skip their larval stage and hatch fully developed little crabs from eggs incubated beneath the female's abdomen, so they do not need to trek to open water to spawn, letting them live their entire life on the islands themselves. Yet this also means that unlike crabs which do spawn at sea and rely on the tides to disperse their young, the quadclaws are endemic only here, and do not occur anywhere else on Serina.

Named for their extremely enlarged fourth leg pair, which are now nearly as powerful as their primary claws, quadclaws are predominately burrowers which retreat to their dens when threatened, leaving their enemies faced with a pair of snapping claws whether they retreat in headfirst or in reverse. So effective is this bodyplan that the small and more vulnerable juveniles of most species start out their terrestrial life with mock eyespots and even pretend antennae in the form of long bristles on their hindquarters, so that predators cannot discern which end is the actual head. By the time they are adults, they have no predators at all, for their thick shell protects them from even the strongest native predator. Though they are in theory highly vulnerable when they molt their shells, only very rarely as adults, they seal themselves deep underground in order to do so and thus ensure privacy and security for the several weeks this process takes start to finish. This thus leaves their only major threat being the cold night - but they have a good defense against this as well.

The colossal quadclaw is a grazer - almost entirely vegetarian - and is well-adapted to endure cold nights as it digs deep, insulating burrow systems to which it is loyal for its entire life. The quadclaw never strays out of sight of its shelter, and feeds only during the warmest time of the day, using its dark shell to absorb solar warmth. This lifestyle suits it well, as its metabolism is slow and its nutritional needs modest. The decline of the forest has in fact benefited this species by giving it a wider range. Normally by day the giant crab simply has to leave its burrow and pluck a few mouthfuls of grass and weeds to fulfill its quota. But it struggles to coexist with the recently established flocks of grazing birds, which feed day and night and are neither limited by the temperature nor a pressing need to remain near a burrow to shelter from the night. Stated simply, the seraphs leave little food for the quadclaw as they land in huge numbers, strip the ground down to the roots, and wander off in search of fresh pasture. Where seraphs appear, quadclaws dwindle, either deprived of food or forced to wander too far from their burrows that they cannot find their way back before night falls and the cold kills them.

It is just another tragedy of the Ultimocene that the colossal quadclaw, despite initially benefiting from recent climate change and seemingly well adapted to it, will soon go extinct. Island species evolve and spend so many generations in a relatively limited ecosystem with few competitors that the arrival of even just one new species which evolved in a more competitive mainland environment can cause an extinction to a less adaptable native species. On Earth, many such events are the result of human introductions. Upon Serina, however, nobody can control where birds may fly and settle. As younger clades such as seraphs born and forged in the wake of the ice age successfully thrive in this ever changing world, their very success inadvertently contributes to the decline of less adaptable species almost as much as the changing climate itself.