Worms became the championship explorers of the Earth. Able to go further, faster and more safely than any colony or single-cell organism could. Swooning across water currents, burrowing into soils these new super-explorers went everywhere they could.
Where an environment was once a lifeless outcropping of rocks with water pools, a dead worm and the organisms tagging along could create an entirely new niche from the death of the worm and the growth of microorganisms around it...feeding even more life on the fringes of the niche, creating further niches.
Although the worms found they were much stronger than the earlier-evolved organisms, they were still limited where they could go by what they could endure. As niches grew so too did competition to reap the best results from an environment.
As wonderful as the worms were and are, they suffered if up against rocks or other skin-piercing they came across in the world conquest. While a diversity of niches opened up, so too a diversity of new dangers arose for these travellers.
Besides slime, some organisms in the brave new wider world adapted to new environmental demands by excreting a new mix of chemicals that instead of increasing the ability to slip and slide in the world, created protection from the environment in the form of hardcore physical armor.
While the Mollusks display classic Succesful Adaptation by having a superiour defense against biochemical and biomechanical threats and predators, along the way, they aslo needed more advanced nervous and muscle systems to manage their new size and abilities.
Not only did this new shell structure defend against jagged rocks but also the ravenous intentions of other worms. Truly ground-breaking, the mollusk shell allowed the organism to not only to have oceans to go in their fluids, but also a mobile cave to escape from especially dangerous foes.
With the advent of mollusca, truly large organisms with very advanced nervous systems could finally evolve. And spread everywhere.
The mollusks themselves are very diverse set of organisms including clams, snails and squids among them, each displaying different types of Succesful Adaptations for their different niches.
As organisms evolved into these differtent places, new ways for the nerve, muscle, skin and organ tissues to interact within the organisms internal environments and the outside environment also evolved.
As did the ability to problem solve for some members of the phyllum mollusca.