Bizarre Life of the Desert Caverns

The Central Dessert of Pangea 2 is the single Most Harsh environment in the late Îledescene as the glaciers grow the world grows drier making the Central Desert well more of a hell hole than it already was. 

Temperatures fluctuate from scorching 40(C) during the day to a freezing -20(C) at night these temperature changes generate powerful winds blowing the sand around like snowflakes tainting everything it touches with a grainy texture. 

Yet below the sandy-laden waste, vast caverns formed from the closing of the Atlantic lay untouched by the hell-storm above. 

These chambers form their own world thousands of miles of brackish subterranean lakes cut off from the rest of the world remain damp and cool all day and where water is plentiful. 

Here under 20 meters of rock life looks like it came straight out of the Cambrian colonies of mineral-eating bacteria forum giant colonies along the cavern walls and floor forming giant mounds on the seafloor their ominous green glow providing the only light in this dark world. 

This world is home to bizarre animals unlike anything else on earth that only live here and can only survive here in their dark water hideaway. And it's below the water beneath the scurrying feet of the Terabytes water carriers that the largest desert animals can be found 

The Diving Hopper is a descendant of the Desert Hopper that has learned to go spelunking into the depths of the caverns looking for food. A habit that was likely started by Desert Hoopers venturing into the surface pools to scrape the algae off the rocks lead to Diving Hoppers diving into the depths of the caves. 

Diving Hoppers now spend most of their day underground feeding on the colonies of underground bacteria coming out of their holes at night to feed on land plants at night. The Diving Hoppers shell helps it in maintaining buoyancy releasing trapped air from there shell and letting them sink into the darkness and kicking off with its foot and filling its shell with water to rise from the depths  

However well it may be safe from the Death Bottle down in the caverns in the darkness they are moving nearly blind with only the light of there food to guide them. 

And unlike most of the world, this land is not the uncontested domain of the mollusks. 

Down here it's their Lophotrochozoan cousins the Annelids that rule this world.  

The Flowering Worm is one of these worms a member of the widespread clade Trichobranchidae that is found nowhere but these caverns. A descendant of the Garden Worm the Blooming Worm retains its ancestor's algae-bearing lobes that they spread wide in the desert sun to perform photosynthesis. These lobes are so effective for the Blooming Worm that it can go for months without eating, surviving purely off the sugars its algae lobs make. 

The Flowering Worm has taken its photosynthetic skin further the tips of its skin now unfold like a flower being able to drop off like petals.

 Being able to shed its algae is its main form of defense shedding the tips of its algae lets it escape the Terabytes' harassment when it's above ground and when it's below ground. 

And it needs defense when it's underground as the cavern's house is one of the largest polychaetes the world has ever seen a descendant of the Slickribbon that sees without sight. 

 The Paropticribbion the meter-long apex predator of the caverns uses its extendable pharynx to wrangle in slippery Flowering and Gloom worms. 

Off course finding their prey is easier said than done when the Paropticribbion is hunting blind but that's where the Paropticribbion's hidden trick comes in.    

The Paropticribbion can see without eyes. Sort of. 

Using a derived fourth set of the Slickribbion's antenna the Paropticribbion can pick up on vibrations in the water made by movement allowing the Paropticribbion to pursue prey without needing eyes. 

The need to process the movements in the water has affected the Paropticribbion's brain parts of its ganglion have specialized for sensory functions stored in the antenna stalks the Paropticribbion is incredibly smart. For an Annelid at least it's smart it's still only about as smart as a catfish.

 Of course, the caveat to its sensory sight is that it detects movement. If something like the Diving Hopper stays still the Paropticribbion won't see it as anything but part of the environment. 

So as long as the Diving Hopper stays completely still it's safe from the much faster Paropticribbion. 

But the slightest movement of the foot will give it away. 

And if that happens it will get the business end of a giant crushing pharynx.