The Endless Desert

The Endless Desert is set in the central desert of the new Pangea, 200,000,000 years into the future. At this point in the future, there are no mammals, birds, reptiles or amphibians. The episode focusses on four species.
Terrabyte - descendants of termites that live in massive air-conditioned underground cities where they farm algae. Each termite is built for a specific role. There are transporters, glue-spitters, diggers and other types too, which form a caste system.
Gloomworm - a simple worm that is descended from a single type of bristleworm which survived the mass extinction.
Slickribbon - a transparent creature with pincer jaws and a nasty sting. It appears to be descended from the same bristleworm as the Gloomworm.
Garden Worm - another descendant of the bristleworm, the garden worm houses green algae in fleshy lobes that stick out like leaves from their backs. The algae convert sunlight into food to feed their host.
With no rainfall reaching the middle of the single continent, the whole place has dried up. Patches of water are rare and in demand. Many of the animals here live in underground lakes and caves to get away from the heat of the desert.