Fibonaccus spinensis
Populations of Fibonaccus garyus living near the coasts of south eastern Aliona began to adapt to living exposed to the air due to pressures from competition and predators. This led to fully terrestrial populations that differentiated into Fibonaccus spinensis.
F. spinensis has a few features that aid in survival on land. The most major adaptation is the ability to breathe gaseous oxygen. This start as vascularized skin allowing them to respire cutaneously. A patch of skin on the back began to form a sac to increase respiratory surface area. The sac was pulled into the front of the shell and utilized muscles to compress and expand to push and pull air. This sac became the primary method of respiration for F. spinensis.
Despite this respiratory sac F. spinensis still needs to live in moist areas such as near water and under leaf litter. The chitinous teeth are reinforced by calcium carbonate to feed on the roots of Plorts and the bones of Tarates to obtain calcium for shell growth. F. spinensis has two adaptations to protect it from predators. The shell has developed pointed processes or spines to make it harder for predators to bite down on the shell. The colors have faded so that F. spinensis is less noticeable. The sensory stalks on the head have developed darkened light sensory cells on the ends to help F. spinensis keep out of the sun.
F. spinensis is still a detritivore, feeding on decaying polyps and musical corpses. It retains much of its ancestral organs and their uses with a genital opening on the foot that leads to the ovaries, an anal opening on the back of the shell that is the combined opening for the digestive tract and gonads. They are capable of self fertilization. They still have a dorsal nerve chord with a centralized brain in the head. The gills have reduced and only provide supplementary respiration.
