Mankind’s influence on Earth was always said to be irreversible, this was not the case. After the reactors blew up, the cities crumbled and the dams gave way, it looked grim. Only the strongest, most adaptable, and most numerous animals could survive. Well, those and any polar animals that survived the global warming that ensued.
After the weather cleared up, Earth began its recovery. Filling the spaces left by long dead species in with remained. The skies swarm with secondarily volant birds and dog-sized cicada-like insects. The impenetrable forests, twisted meshes of pine and palm, are home to arboreal cephalopods, gibbon-like spiders and predatory xenarthrans. The open plains brimmed with life, as herd of grazing, horse-sized dogs run from giant, raptorial lagomorphs. The oceans are ruled by whale sized seals and peculiarly unchanged sharks, trailed by scavenging crocodilians and water-breathing monotremes, with gills in their mouths.
Perhaps even more peculiar than the heavily derived species that roam the surface are the denizens of the underworld. In what was once Mexico, something stirs beneath the ever-shifting sands of a newly formed desert. A small group of rabbit-sized geckos scatter, but nowhere near fast enough, as one member disappears into the jaws of the surfacing predator. At first glance one may think it was some kind of alligator or some kind of caiman. But upon closer inspection… the answer is still nowhere near apparent. It has the same sprawled stature, scaly hide and high set eyes. Perhaps the only feature that betrays the creature’s true nature is the strange nasal crest that adorns its snout.
The animal shifts slightly, basking in the afternoon sunlight. It was far too hot to surface during the day, and so the creature comes up to warm its cold-blooded body. Considering this metabolism, it would make even more sense to consider the creature some kind of fossorial crocodilian. This assumption would be incorrect, which only becomes apparent when the animal fully surfaces. Its slender, meter-long body is adorned with scales and scutes typical of a reptile, its high set eyes are strangely familiar, and the animal’s two digited forelimbs only add to the mystery of its ancestry.
This animal, which has come to be known as the Naola, natavespertilis harenamexicus, is exactly what it’s latin name would suggest. A bat. The creature has diverged so far from its true ancestors that it can barely be considered a mammal. It is completely devoid of hair, save for upward pointing whiskers, and the only notably mammalian trait is the animal’s external genitalia. The Naola is just over a metre long, pushing the limits of a fossorial sand-dwelling animal.
It is one of only a handful of ectothermic mammals, all descendants of bats, all native to the Americas. It is a carnivorous creature, preying upon anything that is stupid enough to pass through its forest of near-invisible whiskers. During the breeding season, the creatures cannot give birth and raise their young in the searing sand, as their cold-blooded metabolism would render the young cooked within hours. To combat this the animals make a dangerous surface journey to solid ground, which could either be the final remnants of a human city, or a rocky outcropping they can dig a den in.
What the future holds for this changed Earth is a mystery, but one thing is sure. The age of mammals is just about to go into overdrive.