From the greek words planitis and streidi, meaning planet and barnacle respectively
This is a recently discovered species on planet Eve's South Eastern continent and the information on it is limited. Unlike most life forms so far that seem to have ancestry in clam/oyster-like organisms, this one shares many traits with barnacles. At first glance, the Planistreidis looks like a regular herbivore with legs designed similarly to the other quadrupeds. From its head sprout a long tongue that acts like an elephant proboscis. Not only can it be used to taste and swallow food, but it can intake fluids and shoot them out. There are also fine fleshy antannae sprouting from the same opening used to pick up scents. There are three pairs of eyes that do not extend like other eyes seen so far but are built in a similar fashion. The are just constricted.
What's really interesting about these creatures is the solid formation on their backs. This is the breeding colony of other Planistreidis who may not have yet reached a mature stage. It appears that the larger individual (carrier) who carries them all is actually sterile and actually exists solely to carry the colony. The latter is regularly fed by the carrier who sprays them with predigested material. All the colony has to do then is lick it off their formation with their long tongues. The formation is actually a biofilm made by the colony to help them stay together and upright (similar to dental plaque). In order to breed, the Planistreidis rubs against rock formations in order to break off a piece of the colony. The pieces that fall off (known as shards) should contain enough individual Planistreidises, each one a hermaphrodite, to fully function.
To grow larger, the shard will continue to be fed by the original carrier. That is until one individual in the shard is capable of growing limbs through the cavities of the biofilm. Those limbs will then sprout their own biofilm and create solid legs allowing it to travel while carrying the rest of the colony on its back. It will now start feeding on taller vegetation and occasionally small insect-like organisms as it grows in size. During that time, the colony will continue breeding until it forms a large pyramid on its back, repeating the cycle.
Since the Planistreidis is a hermaphrodite, it is speculated that should a shard contain a single individual, it still has the potential to grow into a carrier. It may not have anything to carry however.
The front pair of legs of the carrier are longer than the rear pair to allow it to tilt upwards and reach for vegetation in trees.
Although it has a neck, it is extremely stiff and can barely flex. The Planistreidis must rely on its many eyes to keep an eye out for predators at all times.
The individual drawn above is carrying parasites, which can either be removed by rubbing against rocks or by phoresic animals.
Although they are hermaphrodites, Planistreidis still need to diversify. Flying clam-like organisms can actually polonise the colony by transporting spermatozoids in exchange for some food.