Ferrumcarcer
The ferrumcarcer evolved from protosagania. The ferrumcarcer's metabolism is unique; it uses metals to get energy from food in the same way humans use oxygen. To "breathe", it takes electrons off of dissolved iron, called Fe(II). It's a process that produces copious amounts of rust, called Fe(III). Thus it needs sources of hematite to live. It absorbs so much iron that it has iron deposits within the cells. They polarize and make the entire cell like a magnet. This is what gives it its unique cell shape as well as sticks the cells together in neat north to south links. The iron makes it heavy so the cells sink to the bottom. As they multiply they spread over the soil. They cannot move on their own and must be taken to new places via water currents or in dust on land. They reproduce through binary fission.