The Fluttering Spardi split from its ancestor and left the water for broader habitats. Like its cousin, the Sagmalix, its babies lack gills; however, it developed a different solution to raising them on land: the Fluttering Spardi is arboreal, the rope-like legs of its pseudo-radial babies being highly advantageous for clinging to branches. It climbs Petrolignopsid trunks with broad toe pads like those of a Terran gecko or tree frog on all four of its limbs, including its anal arm. Juveniles are capable of swinging through branches using all four of their limbs, while adults will only swing from their anal arm. All digits on juveniles and the anal digits of adults can curl in both directions, allowing them to clutch with the back of the hand.

Juvenile stage

The Fluttering Spardi has also developed patagia stretching from its lateral limbs to its neck and anal arm, allowing it to glide and parachute. It generally uses gliding to get from branch to branch in its arboreal home, and it will parachute by flapping its lateral limbs to land safely on the ground to feed, arboreal food currently being lacking. It mainly feeds on small fauna such as knightworms and crestgills, and it will feed from any carcass it finds as well. It uses its clawed lateral mandibles to grab and carry prey. Like its ancestor, it engages in parental care, bringing food up to its strictly arboreal young.

The Fluttering Spardi hibernates over the winter, generally hiding deep under leaf litter like many Terran frogs. Its thick fat helps prevent it from freezing, though this is far from perfect and many individuals do unfortunately die over the winter, especially in the coldest parts of its range. Still, its reasonably high reproductive rate keeps its population from experiencing any dramatic crashes. Like its ancestor, it has keratin in its skin, though it has even more for the sake of water retention since it doesn’t live around water as much. The additional keratin also prevents its patagia from tearing easily if they are caught on sharp crystals or branches. Its skin is covered in a layer of dead cells which shed over time, not unlike the skin of a Terran mammal.

Like its ancestor, the Fluttering Spardi mates by holding hands with its anal arm and gives birth through a long narrow passage. The female’s cloaca is looser and stretchier than that of its ancestor, dramatically decreasing the risk of tearing it while giving birth. Males produce less sperm than males of its ancestor did; they instead produce very large sperm cells, which compete with and try to block one another along the way down the female’s cloaca, not unlike the sperm of many small fauna on Earth.