Arborgopob
The Arborgopob has split from its ancestor and taken to the trees. Their reinforced lips have evolved into a four part beak which allows them to snip off the crystal leaves of the crystal fortress or young tallstrand crystals. The beak is composed of a cartilaginous core with a keratin and strontium crystal sheath. Food is ground by strontium based nubs in the esophagus and then digested by robust gut microflora that includes ribbon-tailed detriti and several species of denitrifying detritis one of which, Trinucleusdenitrificus detoxicans produces an enzyme that digests the poison of Windcrystal seeds.
The arborgopob's upper limbs are filled with small air and fluid sacs similar to those in their tails enabling them to stretch and wrap around branches. The skin of their tails and upper limbs is thick and rough to grant them increased grip. These upper limbs are also more muscular than those of their ancestor with the gas and fluid sacs acting mostly as a hydroskeleton. Their skin is more resistant to desiccation and UV radiation than their ancestor's and the membrane covering their pinhole eyes has developed a thickened portion that acts as a lens. These eight primitive camera eyes are attached to optic ganglia which help them navigate the three-dimensional maze of tree branches they inhabit.
Their bodies are quite elastic allowing their “torso” to stretch considerably. A series of muscles and gas sacs run between the upper limb girdle, derived from the ancestral “shelves”, and the lower limb girdle. By contracting the muscles they can make their body shorter and wider while squeezing the gas sacs lengthens the torso. Their lower limbs are reinforced with cartilage to provide extra support, though because they have so many gas filled cavities they are lighter then their size would indicate.
Their larger size and more active lifestyle has coincided with the development of a proper circulatory and respiratory system. Paired air sacs next to their vents act as primitive lungs while a quartet of single chambered hearts are located in a ring in the upper portion of the body, one heart between each pair of vents. These hearts and the attached blood vessels are derived from modified fluid sacs. Blood is pumped out and down towards the lower limbs with return vessels traveling back up towards the intestines and lungs. Each heart 's blood flow is unidirectional with each heart receiving the blood pumped out by one of its neighbors usually in a clockwise direction though some individuals have counter-clockwise blood flow.
Like their ancestor most reproduction is asexual. The parthenogenetically produced larva are small, roughly 1 mm long, but well developed with a fully functional digestive system and proportionately large fin-like limbs. These limbs are stiffened with cartilage making them superficially resemble the ocean lantern and enable them to spin down through the air like a terran maple seed. This cartilage is reduced in the upper limbs in adulthood but retained in the lower limbs for support. Adult arborgopobs rarely descend from the trees except during the fall while preparing to mate. Clone larva are usually released from branches overhanging streams or ponds. Thanks to this airborne dispersal stage small colonies of arborgopobs have established themselves on Snow Island and from there they spread to mainland Glicker.